Dear Dr. Staff: How do glasses and contact lenses make it so that people can see better? My pappy said that there's something about the glasses taking the light from what you see and sending it down the earpiece into your ear, but I didn't really understand what he meant and he doesn't wear glasses anyway, so I went to my Uncle Smiley who wears glasses and said that there's these photon things that are really small that are bent when they pass through the lenses, but I don't think he's right, either, because he said that these photon things were round, and I don't see how you can bend something that's round, and besides, how would a bent round thing make you see better?
Dear Hungry Sense: Well, they're both wrong, in different ways. First off, light doesn't come in photons anymore, it comes in waves. (They used to call it the corpuscular theory before they found that corpuscles are in people instead.) But that doesn't matter, anyway. In order to understand how glasses and contact lenses work, I'll have to explain to you how your eyes work in the first place. You know how your glasses have lenses in them? Well, your eyes have lenses in them, too. They focus the light that comes into your eye onto the round surface at the back of your head. As you probably know, your brain is inside your head. And the back of your brain is where the light is focused, so that you can see. People whose vision isn't very good have heads that are the wrong shape, so the lens in the eye doesn't focus it correctly on the inside of their heads. They wear glasses to hold their noses down and make their head the right shape. Contact lenses work by irritating the lens in your eye so that you blink a lot more, and also have hallucinations because it is so irritating. Remember how much it hurt to rub salt into your skinned knee? People soak their contact lenses in salt water when they're not wearing them so that the lenses will hurt more when they put them back in their eyes, and therefore will cause enough pain for them to hallucinate. People who wear contact lenses don't really see, they just think that they are. And people's vision usually gets worse as they age because the fluid around their brain is slowly leaking out, and the back of their brain is drying out (like a prune), which makes it so that they can't see as well.