I can't see things very well at a distance. I used to wear classes, then contact lenses, then nothing. I hadn't worn any corrective lenses for years because glasses were annoying and my contact lenses were messing up my eyes. One day I was thinking about the reason for near-sightedness and I figured that if it's caused by an inability of the eye's lenses to flatten out, then maybe I could physically assist them in some way instead of just optically correcting for the problem like 'corrective lenses' do. Then after trying some things I realized that I could pull back back on the skin at the sides of my eyes and this seemed to do the trick. Since then I've been in several seminars in which I successfully used this trick to be able to read the screen or chalkboard that was too far away for me to otherwise make out clearly. So I decided to make a simple device to do this for me. What I made probably wouldn't be something that most people would want to wear in public, but a professionally made, miniaturized version of such a device might have more widespread appeal, and it was fun to make and test in any case.
Note: Squinting is thought to work by decreasing the amount of light entering the eye as well as by slightly flattening the eye's cornea. The cornea is a lens of the eye that is responsible for a majority of the eye's focusing power. If one squints one can notice a decrease in the field of vision indicating a decrease in eye's aperture. However, when pulling at the eyelid corners with your fingers you will notice an enhancement of distance vision greater than that achievable by squinting, and without any noticeable decrease in field of vision. So it seems that this system works more by flattening the cornea than it does by decreasing the eye's aperture. A final possibility for how this system works is related to the eye's length: In near sighted people light from distant objects converges slightly in front of the retina (the part of your eye that actually detects the incoming light and sends the information to your brain). Using this system the pulling back on the eyelids may be compressing the eye slightly, thereby allowing the convergence of light rays to occur further back in the eye: at the retina, allowing clearer vision of the distant objects.