Eye health problems such as cataracts and macular degeneration usually afflict people in the later decades of their lives. The reason has to do with UVA radiation taking decades to cause sufficient damage for these two eye health problems to become noticeable. There are three types of ultra violet radiation: UVA, UVB, and UVC. UVC is highly energetic but doesn’t reach the earth’s surface because it lacks sufficient penetration power to get through the atmosphere.
On the other hand, UVB has sufficient penetration power to reach the earth’s surface on sunny days when the sky is clear. It’s also energetic enough to give you problems in a few hours in the form of sunburn and snow blindness. UVB is generally a health threat on days when you’re most likely to wear your sunglasses. That is, when the sunlight is fairly intense. UVB also doesn’t penetrate deeply into your skin or your eyes. In fact, snow blindness is essentially a sunburn to the outer surface of the eye’s cornea. In any case, when UVB causes damage, you will know about it in a few hours.
UVA is the least energetic of the three, which is why it can take years and even decades before it does sufficient damage to cause eye problems such as cataracts and macular degeneration. Unlike UVB, it does its damage so slowly that you aren’t even aware of it from day to day. Yet nevertheless, it’s happening every day, and the damage is cumulative.
UVA also has the greatest penetrating power of the three types of UV. It readily penetrates cloud cover as well as ordinary glass. When the sun rises and you’re outside, UVA is reaching your eyes regardless of whether the sky is clear or overcast. In addition, more UVA reaches the ground than UVB, which means there’s more of it reaching your eyes.
UVA also penetrates deeply into the eye and slowly damages its internal structures such as the lens as well as the macula. On days when you aren’t inclined to wear sunglasses, UVA is still slowly damaging your eyes without your awareness. It’s these properties that make UVA so insidious.
Rather than trying to remember to always wear sunglasses every day regardless of the weather, its much simpler to take advantage of VS Eyewear’s prescription lens options and add a UV protective coating on your prescription lenses. The coating won’t add any tint, so your glasses won’t seem any different.
To learn more about our prescription lens options and for answers to your questions, contact us today.