When is sunlight most damaging to your eyes? It’s not what you think
We are told to limit our UV exposure and risk for sunburn by avoiding the hours when the sun is strongest – from 10:00am to 2:00pm. Therefore, these hours are also when our eyes are most at risk from UV damage, true or false?
Surprisingly, the answer is “false”. Our eyes are actually more vulnerable to UV damage between 8:00 and 10:00 am, and then again between 3:00 and 6:00 pm.
When the sun is highest in the sky, our skin becomes most vulnerable to exposure from UV burns. But our eyes are actually more at risk from UV damage when the sun is closer to the horizon. Here’s why:
– The rays from the sun are more “in line” with our eyes during these times, when we are upright (ie. Not in a lawn chair) doing outdoor activities
– Most of us are less likely to put on sunglasses or UV-protective clothing during these times of day
– UV penetration through sunglasses coated with anti-reflection films may actually increase the level of UV light getting through to our eyes (even when the sunglasses have the minimum level of UV protection)
The take-home point is: always make sure you and your family have protective sunwear on at all times when outdoors , not just around noon!
– Dr. Wilk
(Review of Optometry, Practice Pearl of the Week, author: Paul Karpecki, OD, Vol. 3 No. 34)