Many contact lenses sold in the U.S. have dangerous levels of PFAS or toxic "forever chemicals" responsible for serious health hazards such as cancer, liver and kidney diseases, autoimmune disorders and fertility problems, a recent study has found.

The researchers behind the study evaluated 18 popular kinds of lenses and found extremely high levels of organic fluorine, a marker of PFAS in them.

According to the American Chemical Society, per- and poly-fluoroalkyl substances (PFAS) are a class of thousands of persistent, organic fluorinated chemicals used for coating various products for their water and stain-repelling properties. PFAS are called "forever chemicals" because they do not naturally break down.

During the testing, which was commissioned by the Mamavation and Environmental Health News public health blogs, the researchers examined the lenses made by Acuvue, Alcon and Coopervision for organic fluorine at an Environmental Protection Agency-approved lab and found them to have PFAS at levels between 105 parts per million (ppm) and 20,700 ppm, reported.

The testing suggested that the lenses contain fluoropolymers PFAS that make up the soft plastic material used for disposable, soft lenses. All contact lenses contained more than 100 ppm, which is 50,000 times more than the highest level approved to be safe in drinking water by the EPA.

"You could consider [the lenses] almost pure PFAS," Scott Belcher, a North Carolina State University researcher and scientific adviser on contact lens testing, told The Guardian.

Alcon Air Optix (No Hydraglide) for Astigmatism (20,000 ppm), Alcon Air Optix Colors with Smartshield Technology (20,700 ppm) and Alcon Total30 Contact Lenses for Daily Wear (20,400 ppm) were the three contact lenses that showed highest levels of organic fluorine.

The study found that Acuvue Oasys with Hydraclear Plus with UV Blocking (113 ppm) and Alcon Dailies Total One-Day Water Gradient for Astigmatism (106 ppm) had the lowest levels.

The extent of the health effects PFAS in lenses can cause remains unclear, as no previous research has been done to evaluate how the eyes absorb them.

However, the researchers believe PFAS can be absorbed by the eyes since they are generally highly mobile compounds that are absorbed through the dermis layer of the skin. But fluoropolymers are a less mobile kind of PFAS.

The manufacturers need not disclose the use of PFAS in their products as the federal government allows them to claim it as a trade secret. In many cases, these chemicals also get unintentionally added to products throughout the supply chain due to their wide use.

Earlier research has also found the presence of PFAS in products such as toilet paper, plastic food containers and fruit juices.

Contact lens
The researchers who evaluated 18 popular kinds of contact lenses found extremely high levels of organic fluorine, a marker of PFAS in them. Photo courtesy of איתן טל, CC BY 3.0