Pinhole GlassesPinhole glasses are available for purchase here, but we recommend that you first read the below article to understand their value and limitations. How Do They Work?People who need glasses have eyes that are chronically out of focus. In nearsightedness, light rays come to a focus in front of the retina, and in farsightedness the rays come to a focus virtually behind the retina, in both cases resulting in light rays scattered on the retina, which translates into an incomprehensible image, otherwise known as blur. Common prescription lens based glasses (which includes drugstore reading glasses) work on the principle of refraction. Prescription glasses lenses are not flat but curved outward or inward a predetermined amount so that light rays focus precisely on the retina inside the eye, making up for the eyes that are chronically out of focus and providing for a clear image. Pinhole glasses work differently. When an object is viewed through a single small hole, peripheral rays of light, which would normally be striking the cornea (the clear outer layer of the eye in front of the pupil) at an angle, are reduced. These rays are the ones that would make up the "blur circle" in a nearsighted or farsighted eye. By cutting down on the rays of light coming from other objects near what you're looking at, the blur effect in an out of focus eye is reduced substantially. A single pinhole, however, restricts the field of vision substantially, so pinhole glasses are made up of dozens of pinholes to allow for a wider field of vision. The Benefit of Pinhole GlassesThe problem with prescription glasses as described above is the glasses assume a constant "refractive error," or degree of nearsightedness or farsightedness. In order to see clearly through the glasses, a person must continually produce the level of refractive error that the lens was designed to correct for. According to the principles of the Bates method of vision improvement, this means that a person must continually produce a certain amount of strain while wearing the glasses. People improving their vision through the Bates method find that their clarity of vision varies constantly, particularly as they begin to learn to use their eyes right, and a glasses prescription might not be correct any more often than a broken clock. The flashes of clear vision that also come about by persons using the Bates method won't happen, because glasses discourage the eye from relaxing by defocusing the light if the eye were to relax and change focus towards normal vision. Vision improvement is a subtle and sensitive process, and any mechanical discouragement of improvement such as this can easily prevent a person from progressing in improvement. Obviously many people can't do without glasses for all purposes. For some people, putting on glasses results in an uncomfortable or even painful sensation, which is a conscious indication of strain. Obviously many people can't go without glasses for all purposes, and pinhole glasses can be used instead, to use when necessary as an immediate aid to vision, but without the consequences of prescription glasses. When a person's eyes relax and the refractive error lessens or disappears altogether, the pinhole glasses do not discourage it, because they are not made to compensate for a predetermined refractive error, and a focused image will be provided for regardless. Pinhole glasses are therefore useful because they can be used as a flexible aid that provides a sharp image and encourages dynamic improvement of the function of the eyes. A Temporary and Imperfect SolutionYou should also know that there can be certain undesirable effects of pinhole glasses. The multiple holes can create an insect-vision type of effect, with multiple overlapping images, and a flicker whenever you move your head. Due to the multiple holes, the central vision of each eye won't always be focused on the same point through corresponding holes. You have to constantly shift your gaze and/or move your head to have any semblance of binocular vision. This is actually a good thing, because people with chronic vision problems have so much tension and rigidity in the way they use their eyes that forcing them to move more is a step towards improvement. Pinhole glasses are not a legal substitute for situations where prescription lenses are legally required, such as when driving with a vision correction restriction on your driver's license. All in all, they are not a perfect solution, and they are not meant to be so. Their suggested use is as a transitional tool to use during the process of regaining normal vision through the Bates method. Exaggerated ClaimsYou may have come across some exaggerated claims suggesting that pinhole glasses are a complete solution to eliminating myopia or other conditions. Such claims are unwarranted. It's quite possible that some people do improve their vision with the help of pinhole glasses alone, but this would constitute only a small minority, such as people who really only needed to get away from the strain of seeing through prescription glasses and perhaps haven't needed their prescription glasses for very long. Pinholes are suggested here merely as a transitional tool. It is still necessary to use the Bates method to learn to avoid strained habits of seeing, but pinhole glasses may go a long way towards making that process easier. |