Where Do Protein Deposits on Contact Lenses Come From?

You only touch your lenses with clean hands, yet they no longer feel as fresh. Once clear and smooth out of the box, they sometimes seem cloudy or uncomfortable without any visible dust. What changed?

Surface deposits are one possible cause, and their ingredients do not come only from hands or the surroundings. Components naturally present in our tears can remain on lenses too. However, discomfort alone does not identify protein deposits; they are one of several possible causes.

Tears are clear, but they are not plain water

The US National Eye Institute (NEI) explains that tears keep the eye's surface moist and smooth, help focus light and protect against irritants such as dust. Each blink spreads a thin tear film over the cornea.

Oil, water and mucus components contribute to that film. An NEI research overview also describes proteins and mucins in it. Looking clear does not mean containing no other ingredients.

A lens therefore encounters more than a drop of simple water. It stays in contact with tears throughout wear. Components needed by the eye can create a different issue when they accumulate on a lens surface.

Useful tear proteins and deposits left on lenses

CooperVision explains that naturally occurring tear proteins can deposit on lenses and contribute to cloudy vision. Deposits can affect the surface and may be associated with irritation.

This does not mean proteins are bad or that tear components should be eliminated. The issue is material remaining and accumulating on the lens. Thinking about the ongoing interaction between tears and lenses is more helpful than considering them separately.

Clean hands remain important. But washing well does not prove that all deposits during wear have been prevented. Lens care includes hygiene before wear, care afterwards and replacement on schedule.

Cleaning and disinfection answer different questions

Cleaning addresses what remains on the lens surface. Disinfection addresses reducing microbial risk. Even when both belong to one product's instructions, a lens looking clean does not establish that both processes are complete.

The AOA's lens care guide describes rubbing and rinsing when caring for soft lenses with multipurpose solution. Follow the solution manufacturer's method and timing; hydrogen peroxide systems have different procedures.

Do not transfer someone else's product instructions to your own solution. “I soaked them in disinfectant” does not establish rubbing, rinsing, adequate disinfection time or differences between systems. Read the instructions for your current combination of lens and care product.

Daily disposables also come into contact with tears

Daily disposables provide a fresh lens; they do not avoid tears while on the eye. Their surface condition is not irrelevant just because they are daily lenses.

Discarding them after the day's use is part of that system. The AOA advises removing and discarding daily disposables at night rather than cleaning and reusing them. An apparently intact lens is not a reason to wash it and wear it the next day.

Reusable lenses have their own replacement intervals and care instructions. A memory of comfort when new does not justify extending the interval, and thorough cleaning does not make the replacement date optional. Cleaning, disinfection and replacement do not substitute for one another.

Would adding a protein remover solve it?

A product labelled “protein remover” may seem an immediate answer, but adding another product is not appropriate for every lens. CooperVision's care education explains the roles of protein removal and lens care products.

What your lenses need depends on the lens type and care system together. Do not mix in a cleaner intended for another lens or soak longer than instructed. Before changing care, check product instructions and your eye care professional's guidance.

If discomfort repeats, record the exact lens and solution names, opening date, replacement date and when discomfort starts. That provides more useful information than a self-diagnosis of protein deposits.

Before rubbing a cloudy lens for longer

Blur or irritation does not let you identify deposits at home. Lens damage, tear-film condition, prescription, fit or an eye problem may need assessment. Do not simply increase rubbing force or time.

Remove lenses and seek prompt medical care for pain, marked redness or sudden vision changes. We covered these warning signs in when to remove your lenses immediately.

Keeping lenses clear does not mean getting rid of tears. It means understanding that lenses work in contact with tears and following the care and replacement instructions for that lens.