Eye glasses and mirrors

Originally posted by uzless
A much better answer.


Although, I have no idea what makes you think I didn't know the answer. I'd be a pretty lame excuse of a question poser if i didn't know the answer.

I for one can experimentally verify the fact if I look in a mirror, things in the distance are indeed blurry. I have just such a type of vision, myopia, nearsightedness, I can focus on the end of my nose but can't see my own fingers clear if they are held at arms length and when I look through a mirror without my glasses they look just as blurry through the mirror then if I just turn around and look at it directly. Look at it from the inside of the eye and back to the object. The light coming in from distant objects are focusing in front of my retina because my eyes are a bit egg shaped so if you follow the path that the light which is at a point of focus inside and go outside the eye, the line of light still continues to expand when it hits the mirror. Think of a cone of light. If you have a nice cone shaped light, kind of like the light from those little mag light flashlight where you turn the top and the focus changes from a spot to a wider cone of light, if you take that cone of light and shine it on a wall say, 6 feet away, and you see it's 3 feet across, then have a mirror halfway between the flashlight and the the wall, and the mirror is pointing to another wall with the same distance, 3 feet from the mirror which is three feet from the flashlight, the angle of the cone continues to spread at exactly the same angle just as if it were going through the mirror and straight away, but now the mirror reflects that cone of light onto another wall and you find that the size of the cone without the mirror and the size of the cone where you include the mirror in the path but is directed 90 degrees away, the image will still be the same size across in both cases. The angle of the cone of light won't change just due to a reflection. It would be a lot easier just to show you the experiment than to write about it, but the lines from the edges of the cone of light just continue to spread exactly the same with or without the mirror.