Pinhole glasses – well, they are not made of glass, but made of opaque metal or plastic, with many tiny holes on the material. These pinhole glasses can bring about clearer vision in a person with eye refractive errors such as myopia , hypermetropia, presbyopia and astigmatism.
Pinholes help by permitting into the eye only those rays, which pass through the central portion of the pupil, blocking out all the rest. Although this produces a relatively darker image, all of the light rays that enter the eye, now focus directly on the retina. When the user looks through any of the small holes on a pair of pinhole eye glasses, these holes reduce the width of the bundle of diverging rays coming from each point on the viewed object. There is no haziness, just a clear, focused image.
When we wear glasses or contact lenses, the glasses are doing the focusing that our eyes are supposed to do! This of course is not beneficial for the improvement of vision. Pinhole glasses enable one to read and see clearly, but without the negative effects of prescription glasses. They are a natural remedy to many eye problems .