Has UV exposure been linked to eye cancer?
Excessive exposure to the sun's ultraviolet (UV) rays is well known to predispose people to skin cancer, but there’s currently no concrete evidence that it causes cancer in the eye.
UV rays, which you can't see, penetrate the Earth’s atmosphere and reach your skin and eyes in the form of UVA and UVB waves.
The most common type of eye cancer is ocular melanoma, but it is very rare. While “melanoma” is directly linked in our minds to sun exposure, ocular melanomas have no known association with UV exposure.
Can you get eye cancer if you look at the sun?
While exposure to the sun won’t specifically cause eye cancer, UV rays can cause a range of other serious eye conditions.
Common eye conditions that can result from too much UV exposure include cataracts, which is the clouding of the eye’s natural lens. Symptoms of cataracts can include fuzzy vision and sensitivity to glare. Cataracts are the main cause of blindness and are very common as you get older.
Roughly 10% of cataract cases can be attributed to too much exposure to UV rays, according to the Skin Cancer Foundation. And, more than half of Americans over 80 have or will have cataracts due to the natural aging process, according to the National Eye Institute.
Excessive exposure to UV rays also can cause cancers on the eyelids and other sensitive skin around the eyes. Eyelid skin cancers account for 5% to 10% of all skin cancers.
Exposure to the sun can cause:
Macular degeneration is the deterioration of the macula. The macula is in the small center of the eye’s retina, which controls sharp and clear vision. This can impact your ability to read, drive and see things up close.
Photokeratitis, also called snow blindness or welder's flash, is caused by a sunburned cornea. This occurs when your eyes are overexposed to UV rays from a welding torch or reflecting off surfaces, such as snow. What to know: Any vision loss due to photokeratitis is temporary.
Pingueculae are non-cancerous bumps on the eyeball. They typically appear on top of the middle part of the sclera (between your eyelids) and are caused by too much sun exposure. Exposure to dust and wind also can cause these bumps to appear. Additionally, dry eye disease can contribute to the growth of a pinguecula.
Pterygium, or surfer’s eye, is a bump that appears on your eyeball that can potentially permanently disfigure your eye. Pterygium, which is caused by too much time in the sun and dry eye disease, tends to start on the whites of your eyes and, if it is untreated, can progress to the cornea.
SEE RELATED: Primary Acquired Melanosis (PAM)
Types of UV radiation
There are three types of UV radiation: UVA, UVB and UVC.
UVA rays are long-wave rays that account for 95% of UV radiation that reaches the Earth. These rays can pass through your eye’s cornea, reaching the lens and retina inside your eye.
Overexposure to UVA radiation can lead to age-related macular degeneration and can cause some types of cataracts.
UVB rays are the main cause of sunburns, wrinkles, skin discoloration and cancers of the skin. These rays have slightly longer wavelengths and emit higher energy than UVA rays.
UVB rays are absorbed 100% by your eye’s cornea, so they are not likely to cause cataracts. However, too much exposure to UVB rays has been linked to surfer’s eye and snow blindness.
UVC rays are the shortest but the highest-energy UV rays. UVC rays would be the most harmful to your eyes and skin, but the atmosphere's ozone layer blocks virtually all of these rays.
SEE RELATED: UV light
Protecting your eyes from the sun
The best sun protection starts with wearing sunglasses with UV protection when you are outdoors. UV sunglasses must block 75% to 90% of visible light and must offer UVA and UVB protection to protect against 99% to 100% of ultraviolet radiation.
Look for shades that clearly offer UV400 or 100% UV protection on the label. UV 400 lenses provide nearly 100% protection from harmful rays with wavelengths up to 400 nanometers.
Note, too, that UV rays can do damage to your eyes during any season, even on overcast days, so purchase a pair of sunglasses you'll wear year-round.
Additionally, if you spend a lot of time outdoors, consider wearing wraparound UV sunglasses to cut down the amount of UV exposure that may reach your eyes (and the sensitive skin around them) from the sides of your glasses.
SHIELD YOUR EYES FROM THE DAMAGE OF UVA AND UVB RAYS: Shop for sunglasses at an optical store near you or an online eyewear retailer.
Page published on Thursday, March 5, 2020