From front to back: How UV light affects your eyes

We're all familiar with the effects of ultraviolet (UV) light on our skin—suntan, sunburn, freckles and wrinkles. It can also lead to skin cancer.

Our eyes are also sensitive to UV light, and each part of the eye reacts in its own way. From front to back, here's how UV light can affect your eyes.

Eyelid

Basal cell carcinoma and squamous cell carcinoma are two types of skin cancer that occur most often on sun-exposed skin—like the eyelid.

Cornea

The cornea serves as the "windshield" for the eye. It is a clear, protective barrier and must transparent in order for you to see properly. UV light can cause several types of changes in this structure:

Keratitis is an inflammation of the cornea. It's also sometimes called snow blindness and can occur after being exposed to sunlight and reflective surfaces (like snow, water or a sandy beach) without UV light eye protection. 

Pinguecula is a growth that appears on the conjunctiva, the mucous membrane that covers the front of the eye and the inside of the eyelids. The growth can cause irritation and also become infected. 

Pterygium is similar to pinguecula but occurs in a different part of the cornea. It causes irritation and can change the shape of the cornea. 

Crystalline lens

The crystalline lens is transparent and focuses light entering the eye onto the retina. UV light increases the risk of developing a cataract that covers the lens. Left untreated, it can lead to blindness. 

Retina

The retina is a thin layer of tissue at the back of the eye. Cells in the retina process light and transmit signals to the brain through the optic nerve. UV light can damage the macula, the most sensitive part of the retina. This contributes to age-related macular degeneration, an irreversible condition that is the leading cause of blindness. 

One of the most important things to know about UV light is that the effects on your eyes are cumulative. Consistent sun protection starting in childhood is the best way to prevent UV-related damage to your eyes. That means using sunscreen, a wide-brimmed hat and sunglasses with UVA/UVB protection.