The eclipse is happening this afternoon, and you don’t want to miss out — the next total solar eclipse visible from the contiguous United States won’t be for another 20 years. What you do want to miss out on is permanent eye damage because you thought it was probably fine to look at the eclipse without glasses.

It’s easy to think that because it’s darker, the sun isn’t emitting as many damaging rays, and that therefore it’s safer to look at the eclipse than to look at the sun. But that’s just what Big Eye Damage wants you to think. In fact, looking at the eclipse without eye protection is actually more dangerous than looking directly at the sun.

Our bodies naturally avoid bright light by squinting our eyelids or shrinking our pupils to limit the amount of light entering the eye. But when it’s darker, we can open our eyes all the way to let in as much light as we need to see. The eclipsed sun doesn’t emit any more dangerous radiation than it normally does, but because the moon blocks a lot of the brightness, you can more comfortably keep your eyes wide open while you stare at the oncoming rays. Your eyeballs effectively become a big net to catch more ultraviolet rays from the sun than they would otherwise.

So, what does ultraviolet light actually do to your eyes?

It burns them — specifically it burns the retinal cells inside your eyes that need to not be burned in order to function properly. If these cells die, they don’t get replaced. A damaged retina can cause blurry vision, color distortion and even blind spots or rings. It also certainly won’t decrease your odds of developing cataracts later in life.

All this damage comes with a catch — you can’t feel it. Your retinal cells don’t have pain receptors, so you can’t simply stare at the eclipse until your eyes start to hurt. The damage is done secretly, and sometimes the symptoms don’t appear until a few days later.

So, when you ponder whether or not to look at the eclipse with your naked eyeballs, don’t think of it as just the beautiful natural phenomenon it is. Instead, imagine a man shooting a laser directly into your retinas, killing precious and irreplaceable cells. Surely you would be willing to put on a pair of glasses to prevent this evil man from ruining your beautiful eyes.

Fortunately, there are many places to grab a pair of glasses. It’s probably a little too late to have them shipped to your home, but you can buy a pair at your local Target, or, if stopping the laser man isn’t worth $20, thousands of libraries across the country are offering free eclipse glasses. The closest participating library to Pitt’s campus is Green Tree Public Library.

There is ultimately no reason to look at the solar eclipse without proper eye protection. Eclipse glasses are widely available for purchase and for free, and as spectacular as the sight will be, it is simply not worth potentially destroying your vision for the rest of your life. Be safe, and if you really aren’t able to see it, you can always read our reporting on it.