![]() They hit the lens of our eye, but they aren’t let through.īut when the lens blocks UV radiation, that energy has to go somewhere. Ultraviolet radiation has wavelengths that are too short. Infrared radiation has wavelengths that are too long to be visible to us. There are also wavelengths we can’t see, because our eyes block them. Different wavelengths show up for us as green, yellow, blue - all the colors of the rainbow. It is tiny particles oscillating up and down in waves. What gives? The secret is in the type of light and what our eyes do with it.Īll light is actually electromagnetic radiation. But the sun doesn’t seem to affect animals such as reindeer, polar bears and dogs the same way. Humans who live in the Arctic, like the Inuit people, have developed special goggles carved from bone and wood that have a tiny slit or slits that let in only a small amount of light - enough to see, not enough to get burned. But “you’ll look down, and the husky next to you will be perfectly happy,” he told me. When he was out on the snow in bright sunlight, his eyes hurt. ![]() And that was where Jeffery noticed something odd. There, creatures of all kinds have to adjust to long, bright days in summer and long, dark nights in winter. Glen Jeffery, professor of neuroscience at University College London, has had firsthand experience with photokeratitis from the time he spent studying animals that live in extreme visual environments, like the Arctic. (Gabby, if you’re engaging in any of these activities, let’s talk.) There’s even been a reported case of people getting photokeratitis from stage lights while partying in a nightclub. You’re most likely to get it when you’re looking at bright sunlight reflected off a surface like snow or water, but people also get photokeratitis in tanning beds or while welding. Just as in sunburn, ultraviolet radiation from the sun damages the top layer of cells - in this case, those of the cornea, the transparent barrier that covers the front of the eye. There’s a condition called photokeratitis (aka “snow blindness”) that really is similar to the burning, blistery rash that the sun can cause on skin. ![]() But there are other, rarer ways the sun can hurt your eyes. That might happen to you every day of the week, especially in summer when the sunlight is more intense. Jeffrey Goldberg, chair of Stanford University’s department of ophthalmology, wrote to me in an email. The sun is “such an unusually powerful stimulus that the iris muscle is trying to get so small so quickly that it hurts,” Dr. All of a sudden, there’s a lot more light trying to shove its way into your eye at once, and, in an effort at crowd control, your pupil contracts. The pain you feel in your eyes when you look at the sun is similar - you’re doing more work with a muscle than that muscle is used to performing, and doing it faster. Or you stretched your leg and got a charley horse. Have you ever had a muscle cramp, Gabby? Maybe you ran and ran and then your side hurt. Q: Why does the sun hurt my eyes? - Gabby B., age 3-and-a-half I want the toddlers in your life to be a part of it! Send me their science questions and they may serve as the inspiration for a column. With that in mind, we’ve started a new series called Science Question From a Toddler, which will use kids’ curiosity as a jumping-off point to investigate the scientific wonders that adults don’t even think to ask about. Sometimes, their little brains can lead to big places adults forget to explore. ![]() The questions kids ask about science aren’t always easy to answer.
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