Studies show that too much exposure to ultraviolet rays, including UVA rays, can damage the retina. Overexposure can burn the cornea, and repeated exposure over many years can change the structure of the lens so that it begins to cloud, forming a cataract. Left untreated, cataracts can cause blindness.
The Food and Drug Administration requires tanning salons to direct all customers to wear protective eye goggles. Closing your eyes, wearing ordinary sunglasses, and using cotton wads do not protect the cornea from the intensity of UV radiation in tanning devices.
Long-term exposure to natural sunlight also can result in eye damage, but in the sun, people generally are more aware that their eyelids are burning. Under indoor UV lights, exposed skin remains cool to the touch. In addition, the intensity of lights used in tanning devices is much greater and potentially more damaging to the eyes than the intensity of UV rays in natural sunlight.