Many people don't appreciate the difference between a magnifying glass and corrective eyeglasses. While a magnifying glass redirects light rays in such a way as to make an object appear larger, eyeglasses bend light rays so they reposition themselves on one's eye so the images come into better focus. It's the difference between tuning a radio and making the volume louder.

I have a magnifying glass or two lying around the house. I use a little one that can be carried in a purse, wallet or pocket if I might need it while traveling. At home, I use a bigger one. I sometimes need it if I am selling old coins online and cannot make out the mint marks or other tiny details that buyers will want to know about. My regular reading glasses magnify a bit, but they will not help the way a magnifying glass will. I think everyone should have a magnifying glass at home.

We all know looking through a magnifying glass makes objects below the glass bigger. In a telescope, which is used to look at faraway objects on the earth and in the sky, the same principle is used, except the analogue of two magnifying glasses are used, to further boost the magnification. That additive principle of lenses is used also in making prescription glasses today.