Wearing contact lenses can be a convenient and comfortable option for many people who want to improve their vision or change their eye appearance. However, contacts do come with potential side effects. One concern for some contact lens wearers is whether contacts can cause permanent eye discoloration.
What causes eye discoloration in general?
There are a few different factors that can lead to changes in eye color or discoloration:
- Aging – As we get older, the melanin and pigment in the iris can start to fade, making eyes appear lighter or more grey.
- Medications – Some medications, like chloroquine and thioridazine, are known to cause pigment changes and discoloration in the eye.
- Diseases – Certain diseases that affect the pigment cells of the eye, like pigment dispersion syndrome and Horner’s syndrome, can cause permanent discoloration.
- Injuries – Trauma from an eye injury, like a scratched cornea, can sometimes lead to localized discoloration.
- Genetics – Some people are just born with sectoral heterochromia, which causes one part of the iris to be a different color.
Can contact lenses contribute to eye discoloration?
The short answer is yes, contact lenses do appear to come with a small risk of causing subtle eye discoloration over time. However, the discoloration is usually minor and not a cause for major concern.
Some research studies have found associations between long-term contact lens use and discoloration of the iris. A study in the journal Cornea in 2015 used high-resolution photography to analyze the eyes of 202 contact lens wearers and 105 people who did not wear contacts. The images revealed that contact lens wearers were more likely to have dark spots and speckles on the surface of their irises compared to non-lens wearers.
Another study in the journal Optometry and Vision Science looked at 70 soft contact lens wearers and 56 people who did not wear lenses. After taking eye images over 5 years, they found that contact lens wearers developed more visible dark patches and speckling on the iris over time compared to non-wearers.
Additionally, some case reports have documented incidents of people developing blotchy, darker iris discoloration after long-term use of colored cosmetic contact lenses.
What causes contact lenses to discolor eyes?
The exact mechanism behind contact lens related iris discoloration is not entirely clear. However, doctors believe a few factors likely play a role:
- Chronic inflammation – Contact lenses resting on the eye can cause low-grade chronic inflammation and irritation. This could lead to increased melanin production.
- Reduced oxygen – Contacts block oxygen from reaching parts of the eye, which could impact melanocytes and melanin pigment cells.
- Mechanical abrasion – Rubbing between the contact lens and iris can cause microscopic trauma to pigment cells.
- Deposit buildup – Protein and lipid deposits on lenses could theoretically interact with and bind to melanin.
What types of discoloration can contacts cause?
The discoloration caused by contact lenses is usually relatively minor. It consists of subtle dark spots, speckles, blotchiness, or a dusty-looking quality. The most common signs include:
- Nevus – Benign freckle-like lesions on the iris surface
- Stromal dots – Tiny flat pigmented spots clustered together
- Patchy heterochromia – Irregular blotches of different colored areas
- Iris atrophy – Thinning of the iris tissues leading to a diffuse darkened haze
These types of discoloration seem to occur more commonly with soft contact lenses compared to rigid gas permeable lenses. Discoloration also appears more likely with extended wear lenses rather than daily disposables. Using cosmetic contacts such as circle lenses for long periods further increases discoloration risk.
Are certain people at higher risk?
Research indicates some people may be more prone to contact lens-related eye discoloration. Those at highest risk include:
- People with lighter natural eye colors, like blue, green and grey eyes
- Those who have worn contacts for 5-10+ years
- People who wear lenses overnight or for extended periods
- Contact lens users who don’t properly disinfect lenses or replace them regularly
- Those with a history of eye injury, infection, or surgery
- People who wear cosmetic colored contacts for prolonged periods
Can the discoloration spread or get worse over time?
In most cases, the discoloration caused by contact lenses does not appear to significantly progress once it develops. However, there is a possibility it could slowly worsen over many years of continuous contact lens use. The lesion-type spots or speckling may also modestly increase in number.
Switching to daily disposable contacts or taking an extended break from contacts could help stabilize discoloration. But for many people, the spots and color changes already present are permanent. The discoloration also does not pose any vision problems or require treatment in most instances.
When should someone see a doctor?
You should make an appointment with your ophthalmologist or optometrist if you notice any of the following:
- Sudden onset of asymmetric iris discoloration
- Rapid worsening or spreading of discoloration
- Discoloration accompanied by eye pain, light sensitivity, or vision changes
- Areas of discoloration that look swollen, raised, or non-uniform
These types of symptoms could indicate a potentially serious eye condition unrelated to contact lens wear. It’s also a good idea to point out any new areas of discoloration at your next regular eye exam so your doctor can monitor any changes.
Can discoloration from contacts be prevented or reversed?
Unfortunately, contact lens-related iris discoloration cannot be completely prevented in all cases. However, the following tips can help minimize your risk:
- Use daily disposable contacts if possible
- Avoid sleeping in lenses overnight
- Take a break from wearing lenses 1-2 days per week
- Have yearly check-ups to examine lens fit and eye health
- Discard lenses as recommended and never wear lenses past their expiration date
- Avoid cosmetic contacts that alter your natural eye color
For those who already have some iris discoloration from contacts, switching to daily lenses may help limit progression. But reversing the discoloration entirely is unlikely. The pigment changes are essentially permanent, similar to how a suntan or tattoo cannot be removed. However, the subtle color variations are harmless in most cases.
Does contact discoloration increase other eye risks?
There is no evidence that the types of iris discoloration caused by contacts raise the risk for other vision or eye problems. The pigment changes are purely cosmetic.
However, those who develop discoloration may be more prone to other contact lens complications like corneal neovascularization or infections due to factors like poor lens hygiene. But the discoloration itself does not directly increase the chances of developing any vision or health conditions.
Can you still wear contacts if you have discoloration?
If you have noticed iris discoloration from previous contact lens wear, you can likely still wear lenses safely. The speckles or spots do not mean you have to discontinue contact lenses.
However, you may want to consider switching to daily disposable lenses if possible. It’s also wise to give your eyes a break from contacts regularly. Have your vision provider evaluate your eyes annually to make sure your lenses still fit appropriately and your eyes remain healthy.
While the discolored areas won’t go away or cause problems, limiting additional pigment changes may be desirable for cosmetic reasons. As long as your ophthalmologist confirms your eyes are healthy, you can safely wear contacts even with some preexisting discoloration.
Summary
While contact lenses can sometimes lead to permanent iris discoloration, this side effect is usually harmless. The development of dark spots, speckles, or blotchiness seems linked to chronic mild eye irritation and trauma from lenses. Proper lens hygiene and giving your eyes a rest from contacts regularly may help prevent extensive discoloration.
Although cosmetically undesirable, the pigment changes do not impair vision or require treatment. You can typically keep wearing contact lenses safely if discoloration develops. But have your eye doctor monitor for any changes at your yearly exams. While not reversible, the subtle iris color variations are a minor concern compared to the vision correction benefits modern contact lenses provide.
