Alberta gets a lot of sun. As we transition from spring to summer, and people spend more time enjoying the warm weather, we feel it important to remind people to be mindful of their eyes.
In our last blog post, “Sunglasses and Their UV Rating: What It Means for Your Eyes”, we talked about how sunglasses are rated for UV protection. We also talked a little bit about UV radiation, briefly touching on the impacts they can have on our eyes. We’re going to expand on those points here.
There are three types of UV rays:
UVA radiation can pass through the cornea, reaching the lens and retina. In high doses (such as going for a long bike ride without sunglasses), you may experience a condition called photokeratitis (essentially, a sunburn of the eye).
Severe photokeratitis, also called “snow blindness”, is often the result of UV light reflecting off of snow. If you’ve ever gone skiing and come home with sunburns, UV light is why. Snow blindness causes a temporary, but painful, loss of vision.
UVA radiation has also been shown to assist in the development of cataracts as well as macular degeneration.
UVB radiation is what causes the skin to produce melanin (aka, giving you a tan). UVB light has been shown to stimulate the development of cataracts, as well as other serious eye conditions (including cancer of the eye).
Your cornea absorbs most UVB rays.
Now that we have an understanding of how UV rays can harm us, it’s important to understand how to protect our eyes.
Most eyeglass lenses are rated at UV 400 protection. This means they block wavelengths of light up to 400 nanometres, which is somewhere between 99% and 100% of UV rays.
Remember, a lens does not need to be tinted in order to offer UV protection.
Throwing on a pair of UV-blocking sunglasses is a great way to look good and protect your eyes when enjoying the great outdoors. Be mindful that not all sunglasses are rated to block 100% of UV light, though all sunglasses we carry are.
A hat or visor is an easy way to help protect your eyes against UV light. Make sure the one you’re wearing has a brim sufficiently large so as to actually offer some level of protection.
It goes without saying, but never look directly at the sun. The high intensity light and UV rays can cause lasting permanent damage to your retina.
Dr. Lampard graduated from optometry at Pacific University in Oregon in 1981. He and his wife Lorraine have three grown children, all born and raised in Red Deer. Tom enjoys cycling, curling, cross country and downhill skiing, and golfing. He also keeps busy volunteering for the United Way, has been a chairman of the Alberta College of Optometrists, and director of the Alberta Association of Optometrists.More Articles by Tom Lampard