From the brains behind brains on, this is the moment of um.

Answering those questions that make you go,

um... Moment of um comes um, um,

moment of um comes to you from APM Studios. I'm Anna G.

I've worn glasses since I was in second grade. I'm pretty near-sighted, which means I can see things

clearly a few inches from my face. Any farther than that, and without my glasses, my vision is really

fuzzy. I used to be embarrassed to wear them when I was a

kid, but now I think having glasses is pretty cool. I mean, we humans are the only animals

I know of that can make tools that help us see better.

We make telescopes, magnifying glasses, and microscopes too, all to see things that are too

small or too far away for our regular unassisted eyeballs. I know that all of these vision

improvers use pieces of glass called lenses, but I don't know how those lenses

help us see. And I'm not the only one. Jonathan wanted to know too.

Hi my name is Jonathan. I'm from Round Like Illinois and my question is how do prescription glasses work?

In order to understand how glasses work,

you sort of have to start by understanding how the eye works.

I'm Dr. Stacey Pineellis. I'm a professor of

ophthalmology. Ophthalmology is a kind of doctor that treats eye problems and kids and does eye

surgeries. When a person tries to look at an image

for a picture or anything, the image is looked at by having the light rays enter the eye,

sort of like a camera projector.

And the camera projector projects the images

...