Concealers, serums, primers, liners, mascaras, powders, gels, toners, glues, removers. They’re a regular part of many make-up routines around the world and intended to be worn on or near the eyes. While common, researchers are pointing to a bevy of ways these products and more can affect vision and eye health.
In a new systematic review produced by the Tear Film & Ocular Surface Society (TFOS), researchers from across the globe and within the University of Colorado School of Medicine say make-up ingredients, regulation, and other factors deserve closer attention from researchers and consumers alike.
The report is a way to help guide physicians toward available research focused on cosmetics and the ocular surface and show where more focus is needed, says Alison Suhsun Liu, MD, PhD, assistant research professor in the CU Department of Ophthalmology, who helped ensure data quality on the project.
“We wanted to know more about cosmetics and how they’re impacting the ocular surface,” Liu says. “By digging into the research that’s available, we can point others to resources or studies that show sufficient evidence so they can give proper advice to patients.”
Defining cosmetics and cautionary products
Early on in the systematic review, it quickly became apparent that there is no universally-accepted definition for “cosmetics.”
“In addition to that, there is also no standardized minimum safe concentration recommendations,” Liu says. “Each regulatory agency in different parts of the world have their own rules on what ingredients and how much of it are considered safe.”
Those two factors alone mean that each region of the world is different when it comes to make-up trends, ingredients, and regulation.
In the U.S., the Food and Drug Administration estimates 12,500 different chemicals are used in cosmetics, but fewer than 20% of those compounds have been reviewed for safety by the Cosmetic Ingredient Review. Eleven of those ingredients have been banned for use.
There isn’t significant data for many ingredients used in cosmetics applied near the eye, but the researchers note “eyelid skin is relatively thin and permits the easy penetration or absorption of chemicals.”
For eyelash serums containing bimatoprost, for example, studies show success in increasing eyelash length and thickness, but they also increase the “risk of ocular adverse events such as conjunctival hyperemia, compared to a placebo after 4-6 months of use.”
The group says based on the current, best available evidence, physicians should advise their patients that they are at a higher risk of experiencing the condition, which causes itchiness, redness, and irritation, if they used an eyelash growth product.
Eyelash extensions and eyelash glue – which researchers note are both often flammable – were another focus of the report, which highlights multiple studies where participants reported itchiness from the faux eyelashes that are fixed to existing lashes. In one survey of 205 Japanese women, 55% said they “experienced a complication such as redness, discomfort, itch or edematous eyelids” following the application.
“The risks of cosmetics go beyond the physical products and ingredients,” Liu says. “There are also concerns about the tools used to apply make-up.”
They can be a breeding ground for microbial growth. In one study, all of 100 used brushes and sponges sampled were contaminated with Staphylococcus aureus, a bacterium that can cause a variety of illnesses, including cellulitis and abscesses.
Culture and history
TFOS researchers also shine a light on the history of cosmetics and popular cultural applications around the world. Liu says both are crucial to understanding today’s use of make-up, rising trends, and impact on ocular health.
“There are a lot of societal and cultural elements that go into the decision to wear make-up,” Liu says. “In some parts of the world, cosmetics are a must. They're part of the culture or religion, and sometimes even required, so it's helpful for people to understand that there might be potential health impacts on the eye or around the eyes.”
Kohl, for example, has historically been prominent in Islamic religious ceremonies, festivals, and weddings. In the Sunna community, using kohl around the eyes is part of a behavioral guideline. But because preparation practices of the cosmetic have varied and caused systemic adverse effects, strict manufacturing regulations have been adopted in some countries.
Looking at history and culture also gave researchers insight into how ingredients have changed over time and whether regulation has kept up with cosmetic evolution. For example, Halal-friendly cosmetics, which are free from chemicals forbidden by the Islamic religion, have more recently become popular in Middle Eastern communities.
Researchers note there’s also a lot of differences in regulation, which can also impact eye health.
“European countries have stricter regulations compared to places like the U.S.,” Liu says. “But in some eastern countries, there aren’t any regulations at all. It really depends on the local markets, advertising, and ingredients.”
A changing landscape
The cosmetics industry has grown from approximately $80 billion in revenue in 2014 to $103 billion in 2023, and even bigger projections are predicted for the next several years. Trends are constantly evolving, Liu says, and that creates an evergreen need for more research on the topic.
“Cosmetics and use are always being augmented. Everybody wants to do their make-up similar to celebrities and people who are popular in culture,” she says. “Society looks to these figures as a beauty standard, and it completely changes by country or culture.”
Researchers, including Liu, who worked on the TFOS report conclude that there should be more eyes on ocular cosmetics and their potential impacts on eye health. The group specifically highlights a need for more stringent regulation, a universally accepted definition for “cosmetics,” and increased education on ingredients included in products.
“The authors support the recommendation that ocular cosmetics sold commercially list concentrations of all chemical components, as well as provide information about the product’s function, toxicity, indications, contradictions, durability, and expiration date,” the report says.
Liu also points to products that fall neither in the category of cosmetics nor medicine because of semantics or marketing — like some eyelash serums. As a result, they completely fall through the cracks on regulation.
“It’s a very big gray area,” Liu says. “And nobody knows how safe or effective these products are.”