Are pinhole glasses a viable alternative to traditional eyeglasses?
Pinhole (Stenopeic) glasses are a type of corrective eye wear that can improve the vision in persons who are farsighted, nearsighted, have astigmatism or who have decreased vision due to aging. Traditionally, an eye doctor performs a manifest refraction to determine the prescription or power that is needed to properly correct the vision in each eye. If prescription glasses are needed frames and lenses can easily turn into a costly necessity, especially if bifocal lenses are required.
With pinhole glasses, there is no need for a prescription and the same pair can be used to correct both near and far vision. They are made with a series of 1mm dots or holes in an opaque plastic lens. When a person looks through these holes, only central light rays are allowed to pass into the eye and peripheral light is blocked. By reducing the amount of indirect light, the normal blur circle that appears on the back of the eye (the retina) is reduced. Reducing the circle of blur achieves the appearance of clearer vision. While these glasses do not actually improve visual acuity, they do decrease the amount of visible blur.
Pinhole glasses are not ideal for all people and situations and will not entirely replace the need for prescription glasses. There are several limitations to wearing this type of corrective eye wear that should be taken into account. Because the amount of light allowed to enter the eye has been decreased, the need for brighter light to compensate is increased. For safety reasons they should not be worn while driving or outdoors as a replacement for sunglasses. They do not have the proper protection from ultraviolet rays that prescription sunglasses have and their design does not allow for a full range of vision. Stenopeic glasses are best suited for people who have under 6 diopters of myopia and who use them mainly for stationary work such as reading, writing, watching television or at the movies. Despite their limitations pinhole glasses do offer a low cost solution for certain tasks and are worth discussing further with an eye care professional.
