Sunglasses are great for protecting your eyes from UV rays and making it easier to see when you’re driving on sunny days. But did you know sunglasses can even help your night vision? How do our eyes adapt to darkness? When entering dark areas, our eyes go through dark adaptation. This is when they go through a shift where they rely less on the high-resolution cones in our eyes, and more on the low-resolution rods. However, it takes time for this process to occur. The amount of sunlight your eyes receive during the day can affect how your eyes adapt to darkness. Studies have shown that two or three hours of bright sunlight can delay the adaptation of rod photoreceptors in your eyes by 10 minutes or more. Sometimes, full night vision sensitivity may not be reached for hours. After 10 consecutive days of sunlight exposure, nighttime visual sharpness can decrease by as much as 50 percent. Visibility range and contrast discrimination decrease, too. Why is it important to see at night? Clear vision at all hours of the day is key to safety, especially if you drive. More fatal highway accidents happen between 5 p.m. and 7 p.m. than any other time of day, not only because of the number of cars on the road, but because the sun is setting and the changing light can affect vision. Not only can the darkness be a factor, but the glare of the low sun can also be a huge issue. How do sunglasses help? Wearing dark sunglasses during the day can prevent the delay in the shift between daylight vision and night vision. Also, wearing sunglasses with polarized lenses during the day can reduce the sun’s glare, making visibility easier later on, when night falls, CEENTA Optometrist Michael Spicola, OD, said. While it is important for people of any age to wear sunglasses if they want to prevent night-vision issues, it is especially true of people over the age of 50. This is because the eye’s ability to adapt to changing lighting conditions decreases with age. Where can I get sunglasses? CEENTA has 12 locations where people of all ages can purchase both prescription and non-prescription sunglasses. Visit a CEENTA practice near you and see clearly no matter what time of day it is. This blog is for informational purposes only. For specific medical questions, please consult your physician. Do you need an eye exam? Call 704-295-3000. You can also schedule an appointment online or through myCEENTAchart.
