How does sunlight damage the eye?
The sun emits three types of rays: visible, infrared and ultraviolet (UV). The invisible
UV light is the component of sunlight most responsible for eye damage. Excessive
exposure to UV light from light reflected off sand, snow or pavement can produce a
burn on the surface of the eye. Like a sunburn on the skin, eye surface burns are
painful but usually temporary. Eye damage from the sun can happen in one day or
gradually over a lifetime. Repeated exposure to bright sunlight without adequate
protection can damage the cornea (the outer transparent part of the eye that
transmits light to the retina), the lens (the part of the eye responsible for focusing),
and the retina (the innermost layer of the eye that transmits an image to the brain).

UV exposure is a risk factor for:
• pterygium: a fleshy growth that invades the corner of the eye
• cataracts: a clouding of the lens
• macular degeneration: a breakdown of the macula

Who is most at risk for eye damage by UV light?
• People who spend considerable time in the sun or those who live at high elevation
  or near the equator;
• Patients who have had cataract surgery;
• Individuals who have retinal disorders;
• People who are more sensitive to UV rays, including those taking certain medications,
  such as tetracycline, sulfa drugs, birth control pills, diuretics and tranquilizers.

— Sight and Hearing Assocation