Squinting

Try to see something in the same direction where a bright light is shining, and you’ll almost certainly find yourself squeezing your eyelids together, leaving a narrow horizontal slit for light to enter your eyes.

This reaction is understandable! Too much bright light can damage your retina, especially UV light, so it makes sense that we’ve developed a simple defense mechanism designed to keep our sensors safe.

If you know much about how photography works, you already have a pretty good idea of how and why shuttering can be beneficial. A camera uses something called an aperture to limit extra light coming in, helping to keep the area of interest in sharper focus.

When you squint your eyes while looking at something bright, you’re reducing the ability for light to scatter. Only a narrow band gets in, so there’s less information to filter out.

You’re also keeping the image in the center of the cornea, where it’s less likely to be distorted by a bend in the lens. This is why you’ll often…