Dear Dr. Gabe,

How much UV protection does a person need? What does UV light do to the eyes, and is it too early for my 18 month-old son, Jacob, to wear sunglasses?

- Marvin Cullado, San Ramon, CA

Dear Marvin,

Excellent questions! Most people know that exposure to UV – ultraviolet – radiation is a skin cancer risk, but it also causes damage and contributes to diseases that affect different parts of the eye. Most UV exposure comes mostly from the sun. People are also exposed to UV light from tanning beds and certain types of lasers.

UV protection on lenses is the equivalent to SPF sun lotion on your skin. Generally, it is recommended that one should wear glasses that block 99 – 100% of all UV light.

You cannot see, hear or smell UV light, but one can definitely see and feel the effects of sudden and excessive UV exposure in the form of sunburn on your exposed skin - as well as the cornea (the front clear surface) of the eye - known as photokeratitis. And similar to how UV light slowly damages our skin over time, it also has long term, cumulative affects on the eye. Skin cancer can develop on the skin around the eyelids. A pterygium forms as the conjuctiva – the thin and transparent tissue covering the white of the eye - thickens and grows onto the cornea. Inside the eye, long term UV exposure can slowly damage the crystalline lens - making it gradually cloudy and opaque – known as cataracts - as well as the central part of the retina causing age-related damage known as macular degeneration.

Protecting the eyes from UV radiation is something everybody needs, and the earlier the better. Babies and young children are especially susceptible to UV damage because they have more translucent corneas and lenses. A recent study showed that the eyes of the average 18 year old have already acquired as much as 50% of the cumulative lifetime dosage of UV radiation. So, regarding protecting 18 month old Jacob’s eyes, it’s never too early to start! There are a lot of options our there for protecting our eyes from UV light. I’ll go into this in another segment.

-Dr. Gabe