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The Pinhole Glasses ControversyIs Non-surgical Eyesight Improvement Possible
It has been claimed that pinhole glasses improve the wearer's vision - LASIK without surgery. Even if this is untrue, they can be a good alternative to normal glasses.
What are Pinhole Glasses?Pinhole glasses are worn like normal glasses. Instead of transparent glass or plastic for lenses, opaque black plastic "lenses" are used. Wearers see through small holes (pinholes) in the black plastic. How Pinhole Glasses Work - Basic Camera OpticsIn camera terms, pinhole glasses (or spectacles, or eyeglasses) reduce the effect of the eye's focusing errors by increasing optical depth of field by reducing aperture size. This will make sense to photographers. Reducing a camera's lens aperture will make more objects in a photograph come into focus. The effect can be seen by looking through a small hole punched into a piece of paper. A pen or pencil can be used to poke a hole about one to two millimeters across. Even without wearing glasses, an image seen through the hole (held close to the eye, like glasses) will be sharp and clear. There is no "power" for pinholes. The same pair of pinhole glasses can be used by people with different degrees of vision, different power lenses:
Comparing Pinhole Glasses with Prescription LensesVision will not be as clear with pinholes because the black plastic between the pinholes will form a net or web pattern over everything seen. Side-vision can also be blocked (pinholes should therefore not be worn when driving). It may also take weeks or months to get used to pinholes so that the eyes see only one image instead of multiple overlapping images. Despite these limitations some people may find pinholes more relaxing than conventional glasses. Pinholes could be especially beneficial to people who have trouble adjusting to bifocals. However, there is only anecdotal evidence for this, no rigorous scientific studies or surveys. Can Pinhole Glasses Permanently Improve Vision?Claims that pinhole glasses can permanently improve vision are related to claims for the Bates Method of natural vision improvement. The Bates Method teaches people to see only one small point clearly at a time, to quickly scan across an image instead of staring and seeing the entire image clearly without moving the eye. Pinholes train people to do this by creating multiple overlapping images ("fly vision") if the wearer tries to see the entire image without moving the eye. A single image is seen only if the wearer looks through one hole at a time, moving the eye to scan the entire image. However there are no authoritative medical studies supporting claims that eyesight can be permanently improved by either pinholes or the Bates Method. There are individual claims but this is anecdotal evidence, not science. In 1993 the US Federal Trade Commission took successful legal action against companies making such claims (the companies settled out of court). No Cure, No HarmThe main criticism against pinhole glasses is that they do not cure eyesight problems as claimed by some, not that they are harmful (unless used improperly - in the sun, when driving). They do make images temporarily clearer - not by changing the eye but through optical effects (depth of field) outside the eye. Current medical opinion says that when the pinhole glasses are removed, vision returns to how good or bad it was previously. Just like conventional lenses, there is no permanent improvement. ResourcesOptometrists Association Australia on pinhole spectacles Full text of the 1920 book Perfect Sight Without Glasses by William Bates
The copyright of the article The Pinhole Glasses Controversy in Natural Medicine is owned by Yuen Kit Mun. Permission to republish The Pinhole Glasses Controversy in print or online must be granted by the author in writing.
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