How Too Much Sun Can Cause Cancer and Harm Eyes

Sunglasses can prevent eye diseaseThe sun represents a potential threat to the eyes. Overexposure to sunlight can cause an increased risk of cataracts, cancer of the lids of the eyes, and even cornea burns. It is important to prevent eye disease and injury caused by UV radiation and sunlight.

Dr. George Cioffi is the chief of ophthalmology at New York-Presbyterian Hospital/Columbia University Medical Center. He points out that people at elevated risk of eye damage from the sun include cataract surgery patients, people with light colored eyes, patients who have disorders of the retina, and patients whose medications cause sensitivity to light.

Cancer on the eyelid is fairly rare, but one of the major risk factors for eyelid cancer is exposure to UV radiation. Sunlight has both ultraviolet A (UVA) and ultraviolet B (UVB). If you live in an area that has bright sunlight year-round, you are at a higher risk of getting eyelid cancer. Other risk factors include light skin, repeated or severe sunburns, tanning beds, and age (50+). If you notice changes or broken skin that does not heal on the eyelid, consult your doctor.

The cornea is the clear tissue on the front of the eye, and it can be burned from too much sun. Symptoms include pain, bloodshot eyes, blurring, watering, sensitivity to light, and the feeling that something is stuck in the eye. It usually happens to both eyes. Symptoms may not start for 3 to 12 hours after the exposure. This is why sunglasses or goggles should be worn when skiing, and sunglasses are needed when boating or spending time near water on a bright day. A doctor should be consulted with any changed or blurred vision, seeing spots or flashes, or worsening pain in the eyes.

Cataracts is a double-edged sword. The lens of the eye becomes clouded as a cataract grows on top. UV radiation, such as sunlight, is a serious risk factor for cataracts. Many people in their 50’s and older are getting cataracts surgery, and these days, an artificial intraocular lens, or IOLs, is usually implanted.

After having cataracts surgery, patients may believe they are relieved of being vigilant about protecting their eyes from the sun. On the contrary, their cataracts acted like an internal pair of sunglasses that protected the cornea, to some extent, from the harmful effects of UV radiation. People who have had cataracts surgery may be at a higher risk of developing retinal disease because more light is entering the eye and landing on the retina. This is especially true if they have other risk factors such as aging, not absorbing nutrients well, and other health problems that can lead to disease of the eye.

There is no need to cower indoors when it is sunny. Moderate amounts of daily sunlight are needed to improve mood and allow your body to produce Vitamin D. When you are outside in the bright light, wear the right kind of sunglasses. Wrap-around sunglasses are best. Make sure their label says they block 99%-100% percent of UVB rays, and 95% of UVA rays. Amber is generally the best lens color; neutral gray and brown are also acceptable. A hat with a brim is important for protecting the eyes outdoors. And a daily nutritional supplement that contains zeaxanthin and lutein provides antioxidants that help filter light in the eyes, as well as support overall eye health.

Sources: Web MD,, University of Maryland Medical Center