How do pinholes work?
For a person to see images clearly, the light rays entering the eye must come to a focus on the retina at the back of the eye. People who have blurry vision, for whatever reason, cannot see images clearly because the light rays entering the eye focus either in front of the retina or behind it. Pinholes work by permitting into the eye, only the rays which pass through the centre portion of the pupil, blocking out all the rest. Although this produces a slightly darker image, all of the light rays that enter the eye focus directly on the retina. There is no blur, just a clear, focused image. To most people it seems like magic !
