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Sunglasses: Why banning rays is important for the health of your eyes

Vienze Ziction

Not only do sunglasses reduce glare while we’re driving and help us to see more comfortably when we’re outside, but they also help to reduce the risk of eye damage.

This week on “Take Care,” professor of ophthalmology at the University of California Davis Medical School and spokesperson for the American Academy of Ophthalmology, Dr. Ivan Schwab, explains why sunglasses can prevent damage to the eyes and what damage the sun can cause.

Sunglasses are for everyone and according to Schwab, the most important thing to look for when buying a pair of sunglasses is UV ray blockage.  

“The sunglasses you choose should say -- have a little tag or sticker on them -- ‘100 percent UV block.’ UV comes in two forms: UVA and UVB. And UVA and UVB rays from the sun should be blocked a 100 percent. I suppose I might settle for 99 percent because it may be that you can’t filter out 100 percent, but 99 to 100 percent is essential,” Schwab said.

Along with blocking both UVA and UVB, Schwab says having larger sunglasses will offer more protection.

“You want to have large sunglasses, and you want to have wrap-around, if possible, because sunlight can get in through the side of sunglasses. Now, that may not be practical, but if you’re getting sunglasses with 100 percent UV, that’s the best that I can recommend.”

Other factors that play into purchasing sunglasses include darkness, quality of glass or plastic, and, for those who are active, a way to vent your sunglasses to prevent fogginess and even an anti-fog coating.

However, while many of these features are nice to have, you don’t need all of these to protect your eyes. And Schwab says it doesn't matter how expensive your sunglasses are, as long as they have full UV protection.

“You [don’t] have to do these things for eye protection. That’s nonsense, and no one should tell you that. UV protection can be in almost any pair of sunglass if it’s so marked. Even other features are just subtler ways that you may want to think about changing or wearing these sunglasses for your general eye comfort.”

Schwab says it’s as important for children to wear sunglasses as it is for adults.

“Children’s eyes and the skin and the facial area around the eyes [are] forming. This is an important time in child development. As children grow, they’re beginning to develop the cells that they’ll have, producing other cells life-long. So, you need to be sure that they’re protected too… And, yes, children should be wearing [sunglasses], perhaps even more than adults… But, if you take a child outside for very long -- more than a few minutes -- I’d definitely be thinking about sunglasses.”

Schwab says it’s important to protect your eyes from the sun because damage from sunlight can create short term and long term damage to and around the eye.

“Short term: the sun can irritate and damage the surface cell and give what is known as photokeratitis,”said Schwab. Photokeratitis is a disease which can affect those who spend a lot of time out in the sun and enjoying the outdoors, whether it be fishing or spending time out in a dessert or snowpack.

“Basically what happens is the ultraviolet element of the sun will damage the cells on the surface of the eye, degrading vision and creating lots of pain,” said Schwab.

Long term effects of sun damage are more subtle, causing cataracts to form more quickly.