When a person with myopia, presbyopia, hyperopia or astigmatism disorders looks through a hole, the sight becomes clearer: the beam of light hitting the eyes becomes narrower, allowing a larger focus range thus reducing the extent of the blurred area on the retina. This is the principle of the camera obscura, and the hole that has this function is called "pinhole or stenopeic". For those with impaired vision, viewing through a pinhole allows you to focus 60% more than you can perceive with the naked eye. In pinhole glasses, holes are measured, arranged to allow a full range of eye movement, offering the benefits of the pinhole on the entire field of view. Naturalight pinhole glasses are ideal for those who want to reduce the dependence on prescription lenses and tensions associated with sight problems, since using them stimulates the muscles around the eye.