Beauty’s Blind Spot: Unmasking the Ocular Side Effects and Concerns of Eye Cosmetics

Abstract

Nowadays, a significant portion of the population uses eye cosmetics, a trend that is not limited to women, as men increasingly adopt stylish makeup techniques. Eye cosmetics, often termed eye makeup, include a diverse array of products such as eyelash enhancers (mascara, false eyelashes, growth serums, and dyes), eyelid products (eyeliner, kohl, eye contour cream, and eyeshadow), and eye makeup removers. There is a persistent interest among dermatologists in the influence of eye cosmetics on the skin surrounding the eye. The formulation of these cosmetics typically consists of various ingredients, some of which may present potential health risks to users. The application of eye cosmetics is linked to a range of adverse effects on the ocular surface, which may manifest as mechanical injury, tear film instability, toxicity, inflammation, and infections. Therefore, the use of cosmetics in this sensitive area is of paramount importance, necessitating a cooperative approach among eyecare professionals, dermatologists, and beauty experts. Despite the widespread use of eye makeup, its possible ocular side effects have not been sufficiently addressed. This report aims to elucidate how the use of eye cosmetics represents a lifestyle challenge that may exacerbate or initiate ocular surface and adnexal disorders.

1. Introduction

Eye cosmetics, commonly referred to as eye makeup, include a wide range of products, which can be categorized as either leave-on or rinse-off. Leave-on products are designed to remain on the skin for a certain duration, while rinse-off products are applied and subsequently removed shortly thereafter [1]. The tradition of using eye makeup dates back to ancient times, with the purpose of making the eyes more expressive and seductive, while simultaneously promoting an image of youth and beauty [2]. Moreover, superstitious reasons and medical applications were among the other purposes of eye makeup [2].

Nowadays, a significant portion of women use eye cosmetics; studies indicate that 62% of women in the United States regularly apply eye cosmetics, with mascara being the predominant choice. In the United Kingdom, the use of eye makeup is reported at 80% among women [1]. Furthermore, studies show that between 49.7% and 59.4% of women in Korea use eye makeup [3], and in the Netherlands, the percentage ranges from 26.5% to 61.6% [4]. The influence of the glamor industry and social media on makeup application practices is profound in today’s culture. This trend is not exclusive to women; men are also embracing fashionable makeup styles. The popularity of eye makeup products found in ‘toy makeup sets’ designed for children and teenagers has also surged. According to a study in 2016, 54% of American children between the ages of 12 and 14 engage in the use of eye makeup. The valuation of the global eye makeup market reached $15.5 billion in the United States in 2020. Forecasts suggest that by 2028, this market will exceed $23 billion. North America currently holds the position as the largest consumer of eye makeup products, with Europe following closely behind, while the Asia Pacific region is recognized as the fastest-growing market [1].

The formulation of cosmetics usually includes a range of substances such as preservatives, vehicles, antioxidants, fragrances, ultraviolet absorbers, emollients, emulsifiers, and dyes. Some of these components may pose potential health hazards to users [5,6,7,8,9]. The daily application of multiple eye makeup products by individuals can result in the accumulation of these compounds, which may negatively influence eye health.

In an era characterized by the expanding eye cosmetic industry and increasing consumer demand, a comprehensive overview of their ocular side effects is not merely beneficial, but critically important for public health. Alongside consumers, different disciplines, including ophthalmologists, optometrists, dermatologists, and general practitioners should be kept updated. Particularly, ophthalmologists should consider the cosmetic products that their patients use, as well as their application techniques. In line with these purposes, this review empowers consumers with evidence-based information to make more informed decisions about eye cosmetics, helping them to avoid potential harm and advocate for their ocular health. It will also equip clinicians with a more comprehensive understanding of the diverse ocular presentations associated with eye cosmetic use, leading to faster and more accurate diagnoses. There is a pressing need for studies to evaluate the acute and chronic effects of eye cosmetic ingredients. The purpose of this report is to clarify how the utilization of eye cosmetics poses a lifestyle challenge that may intensify or trigger ocular surface and adnexal disorders.

2. Methodology of Search

A meticulous search on PubMed was undertaken to identify relevant articles using the search terms: “cosmetic” OR “makeup” AND “eye” OR “ocular” OR “ophthalmic” OR “eyelash” OR “eyelid” AND “concern” OR “side effect” OR “adverse effect”. Also, the reference lists of relevant reports were screened for further results. The main focus of this report was to encompass industrial cosmetic products (with transient or semi-permanent effects) that can be utilized by consumers on their own. Therefore, rejuvenation treatments, which are predominantly conducted in clinic settings, such as laser therapies, Botox and filler injections, as well as surgical alternatives like blepharoplasty, were excluded. Moreover, non-English publications and those without full-text access were not considered. This search was conducted on 1 February 2025, with no time restrictions.

3. Eye Cosmetics

From approximately 4000 BCE to the 21st century, the advancement of eye cosmetics has been profound. This lengthy timeline has facilitated the introduction of a wide array of products, encompassing a broad spectrum of ingredients and classified into different categories, which have been utilized in a variety of ways (Figure 1) [10].

3.1. Eyelash Cosmetics

3.1.1. Mascara

By darkening, lengthening, and volumizing the eyelashes, this product contributes to a more pronounced and captivating look, making the eyes seem larger. Mascara is available in different forms, including cakes (or blocks), creams, gels, and low-viscosity liquids. Currently, liquid mascara is the most popular modern form. It is anticipated that mascara will take the lead in market shares, followed by eyeliners and eyeshadows [11,12].

3.1.2. Artificial Eyelashes

Although artificial eyelashes, known as eyelash extensions (EEs), are not technically considered cosmetics according to EC Regulation 1223/2009 [10], their application has gained significant attraction in the beauty industry. This procedure consists of attaching artificial eyelashes that are manufactured using a diverse range of materials, including natural substances such as silk, mink, human hair, and horsehair, alongside synthetic materials including polybutylene terephthalate [10]. The extensions typically persist for a period of four to eight weeks [13]. A spectrum of makeup artists, including both highly trained and amateurs, are practicing the EE procedure. Although there is a lack of data regarding the frequency of this cosmetic method, it is increasingly observed that more women are adopting this cosmetic choice in daily life. Considering the difficulties presented by eyelid adhesives, various companies have endeavored to discover alternatives that eliminate the need for such glues. A notable advancement in this area is the creation of magnetic eyelashes, which adhere either to a specially formulated eyeliner infused with metal or to magnets positioned on either side of the natural lashes [1].

3.1.3. Eyelash Growth Serum

Topical prostaglandin analogs (PGAs), such as bimatoprost, target the anagen phase of the eyelash growth cycle, which is essential for the growth of eyelashes and the accumulation of melanin. The application of PGAs may lead to an increase in the number of eyelashes in this growth phase, thereby enhancing the perceived thickness of eyelashes at the eyelid margin. Bimatoprost was rebranded and approved by the US FDA in 2008. Originally, it was authorized for the treatment of hypotrichiasis, but it later received approval for treating trichotillomania, eyelash loss due to chemotherapy, and alopecia areata. It should be applied to the eyelid margin using a small brush before sleep. For maximal eyelash growth efficacy, consistent application over a period of sixteen weeks is recommended [1].

3.1.4. Eyelash Dye and Tint

These products enhance the appearance of eyelashes by making them look darker and fuller. The color can last for several weeks (tinting) or longer (dyeing) [12,14].

3.1.5. Eyelash Perming

Eyelash perming, or eyelash lifting, is a chemical process designed to reshape the eyelashes for a period lasting between 6 and 8 weeks. The immediate effects are generally attributed to the chemicals present in the curling and fixing lotions applied during the procedure [1].

3.2. Eyelid Cosmetics

3.2.1. Eyeliner

Eyeliners are available in different forms, including cake, liquid, cream/gel, or pencil. Currently, liquid eyeliner stands out as a leading option for consumers. Pencil eyeliners, a popular choice in eye cosmetics, are usually applied using one of two methods: either along the inner lid margin or on the skin surrounding the eyes next to the lash line [11,15,16].

3.2.2. Eyeshadow

The application of eyeshadow to the eyelids and the area below the eyebrows serves to create depth and dimension, which enhances the attractiveness of the eyes and highlights their color. It is available in different forms, including paste, cream (or gel), stick (or crayon), pencil, liquid, and powder. Powder eyeshadows are the most common form on the market [11,15].

3.2.3. Kohl (Surma/Kajal)

These cosmetics designed for the eyelids are employed around the eyes to improve their esthetic qualities, resulting in a more expansive, bold, and alluring look. As one of the primitive forms of cosmetics designed for the eyelid margins, this practice persists in popularity across select regions of Africa and Asia [17,18,19,20].

3.2.4. Eye Contour Cream

Eye contour cream, commonly referred to as eye cream, is a specialized skincare formulation aimed at addressing issues related to the sensitive skin surrounding the eyes. Eye creams deliver focused hydration to assist in preventing wrinkles and enhancing skin elasticity. Numerous eye creams incorporate components such as caffeine, which can aid in constricting blood vessels and minimizing the visibility of puffiness. Additionally, certain peptides found in some formulations can assist in diminishing dark circles. Furthermore, various eye creams include ingredients like retinol or hyaluronic acid, which can promote collagen production and reduce the appearance of fine lines and wrinkles. Eye creams also serve to shield the skin from environmental stressors and free radicals, factors that can lead to premature aging [21].

3.3. Eye Makeup Remover

Eye makeup remover serves to simplify the process of removing cosmetics from the eyes and their surrounding areas, thereby improving the overall efficacy of the cleansing procedure. These products are found in different forms, including oils, creams, balms, foams, sticks, water, and saturated pads/wipes. Makeup removers adhere to the solubility principle known as “like dissolves like,” which indicates that substances with similar chemical properties can dissolve each other. So, the use of water is inadequate for the effective removal of cosmetics that contain lipophilic compounds [9,16,17]. Eye makeup removers can be classified into three main types: oil-based, oil-free, and micellar. Micellar removers exploit the oily nature of makeup to attract and eliminate cosmetic products. They create small micelles that can be rinsed off with ease [22,23,24].

It should be emphasized that the purpose of this report is to focus on the ocular side effects of products specific to the eyes. So, other general formulations, such as primers, concealers, foundations, sunscreen creams, and facial masks that can be applied to the eyelids and the periorbital area, are not discussed here. However, these products may contain some overlapping ingredients with popular eye cosmetics [10].

4. Side Effects and Concerns

The use of eye cosmetics is associated with a spectrum of negative impacts on the ocular surface, tear film, and eyelids. These impacts can be manifested as mechanical damage, instability of the tear film, immune responses, toxicity, inflammation, and infections (Figure 2) [17,25].

4.1. Dry Eye Disease

Dry eye disease (DED) is a complex condition marked by symptoms such as dryness and irritation of the eye’s surface, which arise from changes in the tear film’s quality or quantity. While it can affect individuals of any age, it is particularly common among women and older individuals. Estimates suggest that between 5% and 50% of the population are affected by this condition, highlighting its status as one of the most prevalent ocular issues [26]. The tear film plays a vital role in lubricating, nourishing, and protecting the surface of the eye. Composed of roughly 98% water, this clear fluid also contains electrolytes, lipids, and proteins in smaller proportions. The integrity of the tear film is essential for the health of the ocular surface and for achieving clear vision. Disruptions in either the quality or quantity of the tear film can lead to DED. The manifestations of DED can vary, including symptoms such as discomfort, dryness, irritation, burning, stinging, a gritty sensation, and blurred vision. The condition can present mild symptoms or escalate to severe pain and a deterioration in visual function [27,28]. Key elements associated with DED encompass ocular surface hyperosmolarity and inflammation, which may operate synergistically or independently. The pathophysiology of DED is driven by an array of cellular and molecular factors, such as cytokines, chemokines, and metalloproteinases, along with their receptors [29].

The prevalence of symptomatic DED was found to be significantly higher among cosmetic users than among those who do not use cosmetics. Furthermore, individuals who used cosmetics reported greater severity of DED symptoms compared to non-users. Specifically, the most pronounced prevalence and severity of symptomatic DED was noted among users of internal eyeliner and mascara, relative to those who used other types of eye makeup (including external eyeliner, eyeshadow, and eyelash glue). Additionally, the lowest prevalence of symptomatic DED and ocular surface disease index (OSDI) severity was observed in makeup users who regularly removed their eye makeup before bedtime and employed cleansing creams, as opposed to those who did not adhere to a regular makeup removal routine or who used water or soapy water for cleansing [30].

This concern is especially pronounced in female populations, who not only exhibit a higher prevalence of DED but also have a greater propensity for using beauty products. In a research study involving 220 healthy women, the objective was to evaluate the effects of eyeliner and mascara, and their combined application on tear production, tear film stability, and meibomian gland loss. The participants were arranged into four groups: no makeup group, a group that used only eyeliner, a group that used only mascara, and a group that utilized both eyeliner and mascara [31]. Participants were subjected to noninvasive tear breakup time (NTBUT) measurement, meibography, and Schirmer testing. The findings indicated that there were no alterations in the Schirmer test among any of the makeup groups. However, all groups using eye cosmetics exhibited significant changes in NTBUT and meibography when compared to the non-makeup subjects. Notably, the combined application of eye makeup did not have a more detrimental effect on the ocular surface [31]. Meibomian gland loss noted in makeup users could be linked to extended exposure to eyeliner pigments and residual mascara [31].

The “inside liner” eye makeup technique involves applying eyeliner along the edges of the eyelids, specifically over the meibomian glands (Figure 3). Over time, the combination of eyeliner, eyeshadow, mascara, and foundation can mix with sweat and tears, potentially leading to the obstruction of the meibomian glands due to the oils present in the makeup. Additionally, eye makeup can migrate to the ocular surface as a result of blinking or the application of eye drops. Individuals who must use eye drops should be recommended to avoid the application of eye cosmetics. In an observational study comprising 180 participants, researchers found a significant association between the use of eye cosmetics and a decrease in the thickness of the tear film lipid layer [32]. Another study indicated that women who used eye cosmetics were less likely to show foaming at the inner palpebral canthus compared to those who did not. The foam at the eyelid margin was believed to be a mixture of sebum and meibum, and a reduction in foaming was linked to symptoms of dry eye [33].

In order to prevent microbial contamination, cosmetic formulations often contain preservatives. It has been established that various preservatives, such as parabens, phenoxyethanol, benzalkonium chloride, and formaldehyde, can be particularly detrimental to human meibomian gland epithelial cells (HMGECs) [34]. When applied at concentrations that are equal to or below the dosages permitted for human use, these preservatives significantly triggered atrophy and mortality in HMGECs within 24 h of exposure [34].

The application of artificial eyelashes may be associated with the development of dry eye symptoms over time or the worsening of pre-existing ocular conditions. Contributing factors include reduced blinking, incomplete eyelid closure, insufficient closure during sleep, blockage of the glands, dust accumulation, allergic reactions, and mechanical effects. Additionally, the presence of extensions frequently leads to a decline in eye hygiene practices and a reluctance to perform adequate lid cleaning to prevent water exposure to the extensions (Figure 4) [35,36,37,38]. A study was conducted to assess various ocular surface parameters, including the OSDI, conjunctival vascular density, tear meniscus height, NTBUT, bulbar redness, meibography, lipid layer thickness, and corneal staining at intervals of 1 h, 1 day, 1 week, and 1 month after the application of EEs [39]. The results revealed that the sensation of having a foreign body and corneal staining were most intense one hour after application. Additionally, both tear breakup time and tear meniscus height were found to be lowest at the one-week assessment. The other parameters did not exhibit significant changes. Thus, the authors concluded that EEs negatively impact ocular surface homeostasis, particularly during the initial week following application [39]. Another study assessed various factors, including the OSDI, standard fluorescein TBUT, corneal staining, and blink frequency, which showed significant enhancement four weeks after the removal of EEs [40]. The improvement in corneal staining is particularly significant [37,41]. The mechanical effects, along with the chemical agents used for adhesion or removal, may lead to a compromise of the epithelial barrier.

4.2. Allergic Events

The ocular immune defense system consists of innate, adaptive, and mucosal components. The immune system associated with the ocular surface is under precise regulation and control by both innate and adaptive immune responses. The immune response elicited by cosmetics in the ocular region mainly affects the eyelid, tear film, conjunctiva, and cornea [42,43]. Similar to other regions of the skin, the eyelid can develop a contact allergy, which is a form of delayed-type hypersensitivity (type IV), when exposed to a sufficient concentration of an allergen. Cosmetic users may experience symptoms of irritant or allergic contact dermatitis, which can include rashes, blisters, urticaria, and sensations of itching and burning, typically manifesting within 24 to 72 h. The allergen may originate directly from eye cosmetics or may be transferred indirectly from allergens present on the hands [44,45]. Alongside Type IV cell-mediated allergic reactions, the eyelids may also display immediate hypersensitivity reactions of Type I, which can be identified as immunological contact urticaria. This condition typically results in redness and swelling, accompanied by extracutaneous symptoms like conjunctivitis, occurring within a timeframe of 30 to 60 min or later, as a consequence of histamine release. Those with atopic dermatitis are at an increased risk for such immunological responses [46,47].

Reports indicate that contact dermatitis can occur due to exposure to various products, including chemicals present in mascara, nickel in eyelash curlers, and brushes and sponges [45,48,49,50,51]. Regarding EEs, published studies indicate that the adhesive often contains formaldehyde, a compound known to cause allergic reactions in the conjunctiva and periocular skin [35,52,53,54,55]. The pigments employed in eyelash tinting typically consist of black henna and paraphenylene diamine, both of which have been associated with serious conditions such as blepharoconjunctivitis, contact dermatitis, periorbital dermatitis, and eyelid swelling [56,57,58,59]. In 1965, henna received approval from the US FDA for use in hair coloring; however, it was not authorized for application in the periocular region, which includes the eyelids, eyelashes, and eyebrows. Regardless of the type of product utilized for eyelash dyeing, the most prevalent adverse effects are allergic reactions [60]. A five-year prospective study involving 544 participants revealed that 82.6% of individuals using dye experienced a deterioration in their allergic eye conditions [61]. Furthermore, allergic events following eye contour creams are well documented in the literature. To prevent this, it is recommended to apply a small amount of cream initially, select gentle formulations, and avoid any contact with the eyes [62].

4.3. Microbial Contamination

The risk of contamination of cosmetics during their production or storage is a critical issue. Most cosmetics are not manufactured under sterile conditions and are composed of non-sterile base materials. Many cosmetic products include various components that facilitate microbial growth, as they are generally not produced in sanitized media. This microbial contamination represents a serious challenge for the cosmetics industry, potentially resulting in significant economic losses and product failures. The presence of nutrients and moisture in these products makes them particularly vulnerable to microbial growth, which can lead to adverse organoleptic changes, including alterations in color, viscosity, and the development of unpleasant odors. It is posited that contamination arises from neglecting proper manufacturing practices, having inadequate preservation systems, insufficient microbiological testing procedures, and/or failing to establish appropriate microbial limits for completed products [63,64]. The findings of a study demonstrated that both high-quality and low-quality unused cosmetic samples were contaminated with fungi and bacteria. However, the rate and diversity of microbial growth was more pronounced in low-quality cosmetics compared to those of higher quality. This variation may be associated with the specific ingredients utilized, the methods of preservative application, and the conditions experienced during transit and storage [65]. While it is not a requirement for cosmetics to be sterile, in the United States, any bacterial contamination exceeding 100 colony-forming units (CFU/g or mL) in products intended for use around the eye area can lead to regulatory measures and the withdrawal of such contaminated products from the market [66].

In addition to manufacturing issues, poor personal hygiene, prolonged usage, shared application among multiple users, and alterations made by users, such as diluting mascara with water [63,64], may increase the risk of contamination, a condition that poses a significant risk for the development of harmful microbial infections, especially in individuals with dry eyes. Continuous use of a single cosmetic product can result in the introduction of microbes into its packaging. A study found that after three months of individual use, over 35% of mascaras tested positive for microbial contamination [63]. Furthermore, another study indicated that 79% of used mascaras were contaminated with Staphylococcus aureus, and 13% contained Pseudomonas aeruginosa [67]. The degree of contamination correlates with the frequency of use, the product’s age, and the number of users [68]. Sharing eye makeup can act as a pathway for the transfer of Demodex and viruses [69]. As personal microbes accumulate on applicators such as brushes and sponges, it is recommended that these items not be shared among individuals. Sharing cosmetic items within a community may lead to the spread of eye infections. A study involving 484 Malaysian adults found that merely 29% concurred with the notion that sharing cosmetics with friends or family could facilitate bacterial infections. A study conducted on 100 beauty salon tools found that all sampled brushes and sponges were contaminated with Staphylococcus aureus. Additionally, 69.6% of the sponges and 81.8% of the brushes tested positive for Pseudomonas aeruginosa, and fungal contamination was present in 51.5% of the sponges and 30.3% of the brushes [70]. Various forms of eyeshadows, even those in powder form, are vulnerable to the growth of microbes. A study highlighted that 67% of 1345 eyeshadow samples sourced from retail stores exhibited contamination by one or more microbial species [71]. It is recommended to avoid using “testers” in beauty salons that offer open cosmetic products. Also, to mitigate the potential for cross-contamination and the spread of infections, the employment of disposable, single-use applicators is advisable. Moreover, disinfection strategies for contaminated applicators and sponges include the use of 60–80% isopropyl alcohol or ethanol, in addition to UV/UVC disinfection systems [1].

The techniques used in applying eye cosmetics may affect the probability of product contamination and the subsequent risk of transmission to other users [17]. For example, the tip of a pencil eyeliner or an applicator brush that touches the eyelid’s mucocutaneous area is likely to be contaminated with pathogens found in or around the eye. Contaminated liquid eyeliners should be discarded, while the tip of a pencil eyeliner can be sharpened to remove any exposed material, thus reducing the risk of contamination [15,17]. For optimal hygiene, it is recommended that sponges be thoroughly cleaned after each application with a gentle facial cleanser or baby shampoo and subsequently stored in a dry area to avert microbial contamination [1,72]. Regular maintenance of makeup brushes is also recommended, with a cleaning schedule of once a week, employing baby shampoo or a soft facial cleanser [73].

4.4. Mechanical Injuries

The risk of trauma is associated with the application of any cosmetic product using an applicator. A documented case illustrated the deposition of a powdered eyeshadow beneath the edge of a LASIK flap that had been created 6.5 years prior. This incident occurred when the patient was inadvertently “bumped” during the application process. As a result, the flap had to be lifted, the materials removed, and the flap reinserted [74]. In another report, corneal injury was reported when the patient inadvertently poked the eyes with mascara applicator wands [25]. Additionally, employing a pin to address clumpy eyelashes post-application of liquid mascara poses a risk of mechanical injury to the eye. Such open wounds may serve as potential entry points for pathogens, thereby increasing the likelihood of infection. Furthermore, fine nylon fibers found in products, like two-step mascara designed for lash lengthening, can irritate the ocular surface if they become dislodged and come into contact with the eye [17]. In more severe forms, there have also been reports of penetrating eye injury and traumatic cataract formation from an eyelash curler [75]. It is vital to take precautions while applying cosmetics near the eye area. The FDA has cautioned consumers against the practice of applying makeup while in a moving vehicle, such as a car or bus, advising that makeup application should be performed while stationary [43]. Among the other mechanical injuries, there are numerous mechanical effects linked to the use of artificial eyelashes. These effects include lagophthalmos during sleep and calcification at the base of the lashes, which can scratch the corneal surface, and lead to entropion development [1,76]. Furthermore, the use of magnets and metallic makeup close to the eyes has been found to be associated with eyelash loss, which is primarily due to the weight they impose, as well as with corneal abrasions.

4.5. Alterations in Contact Lenses

During the insertion and removal of contact lenses, there is a possibility of them coming into contact with cosmetics, especially when eye makeup is applied while wearing the lenses [77]. A study has demonstrated that cosmetics applied to the eyelash line and eyelid margins can migrate to the ocular surface within five minutes [78]. Previous findings have highlighted the challenges of removing mascara from standard pHEMA contact lenses [79]. Additionally, other research suggests that certain silicone hydrogel lens materials are more likely to retain eye cosmetics, and that cleansing and makeup removal products may influence the physical properties of various lens materials [80,81]. The alterations in lens parameters and image quality are determined by the cosmetics applied, with variations noted across different lens types. Research findings indicate that makeup removers can have a pronounced effect on the diameter, base curve, and sagittal depth of lenses. On the other hand, mascara has been shown to lead to a significant decrease in image quality [77].

4.6. Others

Studies have shown that mascara can obstruct the nasolacrimal duct and canaliculi [82]. Also, it may lead to pigmentation issues and the occurrence of mascaroma, a keratin-rich mass formed from mascara in the palpebral conjunctiva [83,84]. Moreover, its use has been correlated with madarosis, which involves the loss of eyebrows or eyelashes, and milphosis, the loss of eyelashes [85,86].

Eyelash extensions have also been associated with loss of eyelashes [41,76]. Moreover, several case reports have documented instances of eyelids being accidentally glued shut [87]. Notably, it is well-established that both eyelash extensions and the adhesive utilized for their application are flammable. A report highlights the occurrence of eyelash firing during minor oculoplastic surgery [88].

Eyelash dyeing can result in permanent silver staining of the ocular adnexa, known as argyrosis [60]. In rare instances, conditions like xanthelasma palpebrarum may occur [89]. In addition to the discoloration of the eyelids, conjunctiva, and cornea, exposure to silver during the dyeing process may also provoke both benign and malignant lesions, including conjunctival melanoma [90,91].

Oil-free removers can effectively dissolve sebum from the eyelid skin, potentially resulting in dryness around the eyes and aggravating skin issues like eczema [22,24,92,93]. PGAs may lead to conjunctival hyperemia, changes in skin or iris pigmentation, itching, ptosis, trichiasis, and excessive hair growth on the cheeks [38,94,95,96,97].

Table 1. First author, year of publishing, type of study, and main results of the most important studies included (DED: dry eye disease, HMGECs: human meibomian gland epithelial cells, OSDI: ocular surface disease index, TBUT: tear breakup time, LASIK: laser in situ keratomileusis).

First Author, Year	Type of Study	Results
Ghach, 2022	Population-based cross-sectional study	* Individuals who apply cosmetics, particularly internal eyeliner and mascara, are found to have a greater prevalence and severity of symptomatic DED compared to those who do not use cosmetics. * Regularly removing eye makeup before bedtime using cleansing creams (not water or soapy water) can significantly reduce the prevalence and severity of symptomatic DED.
Ercan, 2022	Cross-sectional study	* The combined use of eyeliner and mascara does not result in a synergistically detrimental effect on the ocular surface.
Wang, 2020	In vitro	* Cosmetic preservatives have the potential to cause atrophy and mortality in HMGECs within 24 h after exposure, even at concentrations that are equal to or below the dosages permitted for human application.
Han, 2024	Prospective study	* One-hour post-application of artificial eyelashes, the foreign body sensation is at its peak. * At the one-week mark, tear breakup time and tear meniscus height are at the lowest level.
Grupcheva, 2024	Prospective study	* After a duration of four weeks following the removal of artificial eyelashes, OSDI, TBUT, corneal staining, and blink frequency exhibit considerable improvement.
Mselle, 2004	Case–control study	* The most prevalent adverse effect of eyelash dying is allergic reaction.
Pack, 2008	Randomized controlled trial	* After three months of individual use, up to 35% of mascaras show microbial contamination.
Alshehrei, 2023	In vitro	* Microbial contamination is more evident and diverse in low-quality cosmetics when compared to high-quality products.
Maeda, 2009	Case report	* Inadvertent “bumping” during the application process may lead to the entrance of powdered eyeshadow beneath the edge of a LASIK flap, even several years after surgery.
Ramasamy, 2010	Case report	* Open-globe injuries can be seen by makeup tools.
Luensmann, 2015	In vitro	* Makeup removers can have a pronounced effect on the diameter, base curve, and sagittal depth of lenses. * Mascara can significantly decrease the image quality of contact lens wearers.
Goto, 2010	Semiquantitative study	* Cosmetics applied to the eyelash line and eyelid margins can migrate to the ocular surface within five minutes.

provides an overview of the most important studies included.

5. Can “Do-It-Yourself” Approach Solve the Problems?

Some consumers are increasingly cautious about specific health products, particularly in the cosmetics sector. This caution may encourage them to adopt a do-it-yourself (DIY) approach, crafting these products independently. A study involved the collection and analysis of recipes of 275 DIY products sourced from blogs and social media [98]. The products included a variety of categories, such as eye makeup, eye makeup removers, eyelash products, and eye contour care items. A review of internet-based recipes indicates a considerable degree of heterogeneity and uncertainty regarding the specified quantities and ingredients [98]. For example, numerous mascara recipes suggest the use of activated charcoal as the black pigment. Unlike other ingredients, some recipes suggest utilizing charcoal in the form of tablets or capsules. The various forms available on the market contain differing levels of charcoal. Activated charcoal is sourced from materials that are inherently high in carbon content. The production processes for charcoal do not eliminate the risk of toxic substances, which could adversely affect human health. Consequently, some of these recipes may inadvertently include heavy metals such as cadmium, antimony, tellurium, mercury, thallium, or lead [99,100,101]. Given that exposure to heavy metals is associated with several ocular conditions [102], it is imperative to advise against the use of charcoal-based products unless their quality can be assured prior to use. Also, there are considerable variations in the types of additives utilized to ensure the effective preservation of produced items. Furthermore, the application of antimicrobial preservatives is minimal, if present at all. Finally, after the preparation process, essential physical or chemical parameters, such as pH levels, isotonicity, and sterility, are not checked [98]. Collectively, it seems that DIY formulations designed for application in the eye or surrounding areas are potentially unsafe, and their usage may lead to significant adverse effects.

6. Discussion

The eyes are commonly viewed as the windows to the soul and a vital communication tool. Centrally situated on the face, the eyes often attract significant attention in conversations about cosmetic enhancements. The COVID-19 pandemic has further heightened this focus, as they are the sole facial feature visible while masks are in use. The unique anatomy of the periorbital region makes it the initial area to be noticed and affected by observers. A youthful face typically features full eyebrows and skin that exhibits both volume and elasticity. Moreover, the integrity of the tear film is essential for esthetic considerations. The Purkinje images reflected in a healthy tear film contribute to the formation of visually appealing reflections [103]. The images we observe significantly influence our perception of the eye, commonly described as having a “sparkle”. Disruption of the tear film due to ocular surface disorders can lead to a reduction in this perceived “sparkle” [103]. One of the most important components to having a healthy tear film is cilia or eyelashes. Eyelashes serve multiple protective functions for the eye. They initiate a reflexive response to potential threats, shield the eye from airborne particles due to their curved structure, assist in retaining moisture by reducing airflow, filter sunlight, and contribute to esthetic appeal. Each eyelid typically features 2 to 3 rows of lashes. The upper eyelashes are generally more numerous, ranging from 100 to 150, and are longer, measuring between 8 and 12 mm, with a characteristic upward curve, in contrast to the lower eyelashes, which number between 50 and 75 and measure 6 to 8 mm in length [104]. One to four eyelashes are lost and replaced daily. The optimal eyelash length equals 0.35 ± 0.15 times the eye width, averaging around 12 mm [105]. Changes in the volume, length (such as with artificial lashes), and curl (as with lash lifting) of natural eyelashes can interfere with their ability to deflect debris and limit tear evaporation [2,105,106,107].

The demand for cosmetics designed to enhance beauty is on the rise, driven by societal pressures, the continuous stream of information from social media platforms, and the COVID-19 pandemic. The increased use of video conferencing during the pandemic has led to a greater focus on facial features, notably on the eyes [108,109]. According to the US FDA, cosmetics are defined as substances intended for application to the human body through various means, including rubbing, pouring, sprinkling, or spraying [110]. Their primary functions include cleansing, beautifying, enhancing attractiveness, or altering physical appearance. Of the more than 12,500 chemicals present in cosmetics, fewer than 20% have been assessed by the Cosmetic Ingredient Review, an independent organization that works in conjunction with the FDA [34]. Unfortunately, even though cosmetic products are commonly used, there is a lack of regulatory oversight from U.S. law regarding these products and their ingredients, meaning that FDA approval is not necessary before new cosmetics are launched [111].

Throughout the COVID-19 pandemic, there was a notable reduction in the production and distribution of eye makeup. Also, the way by which consumers acquire their ocular cosmetics has changed. Traditionally, the majority of beauty products were purchased from physical stores; however, there has been a notable shift towards online shops. The influence of social media platforms on the online sales of eye makeup is considerable. However, consumer decisions about eye makeup purchases are not only guided by engaging digital content; they are also significantly affected by the views of close friends and family, along with the impact of celebrities. Overall, it seems that consumers seem to be leaning towards the personal stories of influencers when making choices, rather than relying on the principles of evidence-based medicine. An online survey conducted among 169 users of cosmetic products revealed that, despite the extensive range of available options, only 30% of participants took the ingredients into account when making purchasing decisions [107]. As another witness, a study has shown that users generally have a very limited understanding of the materials used in extensions and the adhesives that facilitate their attachment. Their primary focus tends to be on esthetics, ease of maintenance, and, for a small subset, the cost. Health consequences were not considered; users were primarily interested in achieving a “superstar look” without awareness of the potential toxic and allergic reactions, as well as damage to the ocular surface that these components might cause [40]. So, I believe that increasing public knowledge seems to be a critical step in decreasing cosmetics-related side effects. The potential of blogs and online platforms to connect with extensive audiences and achieve notable prominence is considerable. As an illustration, in 2017, Instagram recorded 800 million monthly active users worldwide, whereas Pinterest had 200 million. Yet, bloggers have limited understanding of the ingredients used in the products. Hence, social media can act as a great opportunity and space for policymakers to interact with.

The incorporation of eye cosmetics into daily life poses a notable challenge. The products and procedures associated with eye cosmetics can result in a range of adverse effects, which may not only cause harm but also worsen existing issues or encourage the emergence of diseases affecting the ocular surface and its surrounding tissues. Evidence suggests that the occurrence of eye discomfort is more pronounced among individuals who regularly apply makeup than in the average population [17,112]. Many of the components found in these cosmetics have the potential to harm the ocular surface and its associated structures. The role of cosmetic ingredients is diverse, particularly in eye makeup, where they are utilized for various functions including absorption, antimicrobial activity, antioxidant properties, buffering, coloring, emulsification, pH adjustment, preservation, ultraviolet protection, and as solvents or surfactants.

Most eye cosmetic products do not possess true “sterility” in the same strict manner as ophthalmic pharmaceuticals like eye drops, which are typically produced under aseptic conditions and undergo terminal sterilization. Instead, eye cosmetics are generally manufactured to fulfill microbiological cleanliness standards or “low bioburden” requirements [66]. This signifies that manufacturers aim to limit the presence of microorganisms during the production and packaging phases, often through the implementation of good manufacturing practices, the use of preservatives, and comprehensive quality control testing. The goal is to ensure the product is free from harmful levels of pathogenic microorganisms at the time of release. Formulations often include preservative systems designed to inhibit microbial growth. However, the efficacy of these preservatives can be compromised over time or with improper use. Once an eye cosmetic product is opened and used, its sterile (or microbiologically clean) state is immediately compromised due to several factors: repeated contamination from the user, direct contact, tears and mucus, finger contamination, environmental exposure, a warm and moist environment, and breakdown of preservative systems. The direct consequence of this microbiological contamination is the introduction of a non-sterile product into the delicate ocular environment. This poses significant risks of ocular infection, allergic reaction, as well as irritation and inflammation [63,64,65]. To mitigate these risks, the following instructions are recommended: adhere to period-after-opening dates (maximum time to use the product once opened), avoid sharing, apply makeup with clean hands, replace after eye infections, avoid adding water or saliva to the products, store products in a cool, dry place away from direct sunlight, and discard products that change in color, odor, or consistency.

A variety of chemicals are utilized in cosmetic products as preservatives. Commonly employed preservatives in the cosmetic industry include benzalkonium chloride (BAK), formaldehyde-releasing agents, parabens, phenoxyethanol, and chlorphenesin [112,113,114,115,116,117,118]. Notably, these compounds mostly pose a risk to the ocular surface structures, even at concentrations that are hundreds of times below the established safety limits for cosmetic products, potentially causing ocular discomfort and various symptoms. BAK serves as the primary preservative. Its detergent-like properties, while effective against microbes, can disrupt the lipid layer of the tear film, leading to increased tear evaporation and dry eye symptoms. BAK has been shown to exert cytotoxic effects on corneal and conjunctival epithelial cells and can contribute to subclinical conjunctival inflammation, epithelial hyperplasia, and goblet cell loss. This disruption of the ocular surface can manifest as discomfort, foreign body sensation, burning, redness, and superficial punctate keratitis. Chronic exposure to BAK has also been linked to mitochondrial dysfunction in ocular cells [119,120,121]. Another category of preservatives frequently found in cosmetic products consists of compounds that release formaldehyde (FA) [107,115]. Importantly, a study revealed that BAK and FA are toxic to iHMGECs, iHCECs, and iHConjECs, negatively affecting their morphology, survival, and ability to proliferate, even at concentrations that are hundreds or thousands of times below the established safety thresholds [111]. The delicate nature of the periocular skin and the ocular surface makes them particularly vulnerable to the effects of cosmetic preservatives. Many preservatives can destabilize the tear film by disrupting its lipid and aqueous layers. This leads to increased tear evaporation, hyperosmolarity, and characteristic symptoms of DED. This effect is compounded in individuals with pre-existing dry eye or are contact lens wearers. Chronic exposure to preservatives can induce a low-grade inflammatory response on the conjunctiva and cornea. This can lead to cellular damage, loss of goblet cells, and changes in the corneal epithelium, affecting its barrier function. The skin around the eyes is thin and highly permeable, making it susceptible to allergic reactions or irritation from cosmetic ingredients, including preservatives. Symptoms can range from mild redness and itching to more severe swelling, blistering, and eczematous changes. These reactions can occur immediately or develop after prolonged use due to sensitization. Some preservatives, along with other cosmetic ingredients, can obstruct the meibomian gland orifices or be toxic to the meibomian glands themselves. These glands produce the essential lipid component of the tear film, and their dysfunction is a leading cause of evaporative dry eye. While immediate reactions may be mild, the cumulative effect of daily exposure over months or years can lead to more insidious and chronic changes to the ocular surface, even if subclinical [119,120,121]. In summary, preservatives act as a double-edged sword: essential for product safety, but potentially detrimental to ocular health with frequent use. In light of potential toxicity to the eyes, it is crucial for consumers to be more conscious of the ingredients found in cosmetics. However, it appears that relatively few individuals are sufficiently informed or driven to examine cosmetic ingredients.

While not intentionally added as ingredients, various heavy metals can be present in eye cosmetics as impurities or trace contaminants, primarily stemming from naturally occurring minerals used as pigments or from the manufacturing process. Several heavy metals have been detected in eye cosmetic formulations, including lead (Pb), arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), chromium (Cr), and cobalt (Co). Their presence, even in small amounts, raises significant health concerns due to their potential for accumulation in the body and their inherent toxicity. The ocular side effects of heavy metals in eye cosmetics can range from immediate irritation to chronic conditions. Contact dermatitis, conjunctivitis, dry eye disease, direct toxicity to the epithelial cells of the cornea and conjunctiva, and pigment deposition are among the ocular side effects linked to the heavy metals found in cosmetics [122,123].

Cosmetic products can lead to inflammatory conditions that primarily involve the cornea, conjunctiva, tear film, and eyelids. The damage to the cornea and conjunctiva can be classified into three categories: physical injuries resulting from improper operational procedures, irritant or toxic effects from specific chemical components in the cosmetics, and infections that may develop from the use of these products. Dermatological evaluations are important for detecting skin reactions to eye cosmetics; however, the unique anatomical and physiological characteristics of the eye necessitate the involvement of ophthalmologists in the observation and management of ocular side effects. Conditions like dry eye disease, infections, chemical injuries, and mechanical damage can adversely affect vision and ocular health. The diagnosis and management of these conditions are the responsibility of an ophthalmologist. Therefore, both dermatological and ophthalmological assessments are vital for a thorough approach to patient care after adverse reactions to eye cosmetics.

Table 2. Recommendations to decrease the risk of eye cosmetics-related side effects.

Recommendation
1. Avoid using eye makeup if it is essential to apply eye drops.
2. Avoid sharing cosmetics with other persons.
3. Avoid using testers in beauty salons that provide open cosmetic items.
4. Use of one-time, disposable applicators in beauty salons is recommended. Otherwise, disinfection strategies for contaminated applicators and sponges should be employed.
5. Sponges need to be completely cleaned following each use and kept in a dry location.
6. Makeup brushes should be regularly cleaned once a week.
7. Avoid applying makeup while in a moving vehicle.
8. Discard old eye cosmetics; for example, mascara should be thrown away three months after purchase.
9. Never use saliva or water to moisten eye makeup.
10. Avoid storing cosmetics at temperatures exceeding 85 degrees Fahrenheit, as this can lead to the breakdown of preservatives.
11. Avoid using eye cosmetics if there is eye infection or inflammation in the surrounding area.
12. Cease the use of any cosmetic that causes irritation.

summarizes the recommendations that can be employed to decrease the risk of side effects.

A slit-lamp examination of the tear film may demonstrate the existence of small particles and pigments that are derived from eye makeup and are suspended in the tear film. Cosmetics found in the tear film may be a consequence of straightforward migration, poor application methods, or the frequent rubbing of the eyes [124]. An additional hypothesis suggests that the activity of the Riolan muscles, characterized by a set of vertically aligned fibers located just beneath the palpebral skin surrounding the eyes, might also be significant in aiding the migration of particles along the eyelid margin [124]. The surface tension of the tear meniscus creates suction forces that may assist in drawing cosmetic products situated close to the lid margin toward the ocular surface [125]. Several studies highlight the movement of compounds through the lid margin, a process driven by the development of new ocular drug delivery methods that avoid the direct instillation of medication onto the eye [126,127]. The negative impact of eye makeup removal products on tear film characteristics has also been documented. A clinical study conducted in vivo revealed that these removal products can migrate into the tear film after being applied to closed eyelids [22]. Topically applied products have the potential to disperse up to 1 cm from the area of application. In particular, cosmetics meant for periocular regions can frequently access the meibomian glands and the ocular surface [128]. Regardless of the etiology, such interactions can reduce the delivery of meibum to both the eyelid margin and the tear film. Beyond the makeup products themselves, the tools used for application can significantly influence the health of the ocular surface and surrounding structures. The primary categories of makeup applicators include brushes and sponges. A major issue associated with these applicators is their capacity to serve as breeding grounds for microbial proliferation. The presence of skin oils, debris, and moisture can foster an environment conducive to microbial growth. The ocular surface microbiome of eye cosmetic users shows some alterations. For example, users of oil-based eye cosmetics tend to have higher occurrences of Demodex mites, a common parasitic condition affecting eyelash follicles that can lead to duct blockage. This infestation is particularly common in older individuals with dry eyes, who may experience symptoms such as itching and cylindrical dandruff [129,130].

There is a persistent interest among dermatologists in the influence of eye cosmetics on the skin surrounding the eye. Hence, the application of cosmetics in this delicate region is critical, warranting a collaborative effort among eyecare professionals, dermatologists, and trained beauty specialists. In summary, this report provides a broad range of eye makeup-related side effects and practical recommendations to prevent them. Moreover, by systematically outlining documented side effects, this report provides evidence that can inform stricter guidelines for ingredient safety, product testing, and labeling requirements. For the cosmetic industry, this work underscores the importance of prioritizing product safety and transparent communication, potentially fostering the development of safer formulations.

7. Conclusions

Despite the popularity of eye makeup, its potential ocular side effects have not received adequate attention. During standard ophthalmic consultations, ophthalmologists often encounter inquiries regarding the side effects associated with eye cosmetics. Generally, these side effects can be divided into three distinct categories: mechanical damage, irritative or toxic responses, and infections. It is strongly advised that individuals refrain from using eye cosmetics if they are currently suffering from ocular surface conditions such as dry eye disease or are scheduled for an ophthalmic procedure in the near future. At present, it appears that consumers are significantly swayed by social media platforms, rather than adhering to the foundations of evidence-based medicine. Therefore, enhancing public awareness is essential to minimize the adverse effects linked with cosmetics.