When looking through a hole, those who suffer from myopic, presbyopic, hyperopic or astigmatism disorders are able to obtain clearer vision: the beam of light hitting the eyes becomes narrower, allowing a wider focus range and reducing the size of the unfocused area on the retina. This is the principle of the camera obscura, and the aperture that provides this function is known as a "pinhole". For those with impaired vision, looking through a pinhole allows a view that is 60% more "focused" than that which can be perceived by the naked eye. In the case of pinhole glasses, the perforations are measured out in a specific arrangement that allows a full range of eye movement, providing the benefits of pinhole vision across the entire field of view. Since their use stimulates the muscles around the eye, Naturalight pinhole glasses are ideal for those who want to reduce the eye strain associated with vision difficulties and their dependence on prescription lenses.