Seeing with closed eyes

I’ve been working on my laser pointer recently, and in the course of my work I made an interesting biological discovery. Laser pointers are ridiculously bright. You can shine them on a finger and they’ll light up the finger so that you can see it from the other side.

You’re not supposed to shine lasers directly into the eye because they are so bright. Most laser pointers, though, are class 3 or lower, meaning they won’t do permanent damage if exposed briefly. Still, my eyes are not something I like to risk, so I don’t shine it into my eye intentionally.

However, in the course of fiddling with the pointer while waiting for a process, I held it against my temple, turned it on absentmindedly, and saw some red. At first I thought that the laser must be reflecting off of something and getting into my eye somehow, but it didn’t make any sense. It was a blurry red light and was clearly more intense closer to my temple. The light wasn’t escaping outside and reflecting off anything, either, because the laser was directly against my temple. I concluded that the light was actually traveling through my temple and into my eyeball and hitting my retina without going through my iris.

This is not a huge discovery. In fact, you can simulate the effect quite easily with nothing but a bright environment. Close your eyes. Then put your hands in front of your eyes. It gets even darker. With just your eyes closed, light is still passing through the lids and into the eye. With the temple, it just takes more light to get through to the retina.

I’m not too concerned about losing my eyesight from doing this, but I’m not going to keep doing it. It’s interesting that I can see things without having it go through the front of my eye.