I have been having trouble with my vision. blurry and shadows. I realized that when I use a hand held mirror to see the back of my hair that is being reflected by another mirror behind my back I can see so much clearer. why is this? Eye dr. has not been able to help me so far.
What comes first to mind is the fact that the distance from eye to mirror to mirror to back of your head is a relatively long distance. You could try looking at the back of someone else's head (or a printed page or anything else with a lot of detail) at various distances and see if there's a distance at which you see better detail. If that doesn't work, then I would lean toward @Steve 's guess that one of your mirrors might be distorted. You could test that guess by using a different mirror. Either situation would suggest that you need different eyeglasses.