Pinhole glasses , also known as stenopeic glasses , are glasses with pinhole needle sizes filling in a blank plastic sheet in each lens. Similar to the workings of pinhole cameras, each perforation allows only very narrow beam of light to enter the eye which reduces the size of the confusing circle on the retina and increases the depth of the field. In the eye with a biased error, the result is often a sharper image. However, a second effect can appear on the common bridge between each of the two adjacent holes, where two different light rays come from the same object (but each pass through different holes) that diffract back toward the eye and to the place different in the retina.. This leads to double vision (objects that have multiple edges) around the edges of any non-focal holes in the eye, which can make the overall image bothersome and tedious to look at for a long time.
Unlike conventional prescription glasses, pinhole glasses produce images with no bearing effects around the edges (which makes the straight line appear curved). While pinhole sunglasses are claimed to be useful for people close and distant, they are not recommended for people with more than 6 diopters of myopia. In addition, pinhole glasses reduce brightness and peripheral vision, and thus should not be used for driving or when operating the machine.
Traders claim that after long use, the plastic grille will become easily ignored. However, each time the user blinks, the horizontal lines of the grille will appear thicker. This is because the eyelids moving above the pupil will reduce the amount of light that falls into the retina and thus will briefly eliminate the lateral inhibitory effect that usually makes all holes appear larger (and the lattice appears thinner). So, as long as the user keeps flashing, they will continue to be reminded of the dark grille covering their eyes.
Needle pinhole glasses have been marketed by various companies on a claim that - combined with certain eye exercises - they can improve vision permanently. However, no scientific evidence was found to support this claim. Due to the lack of formal clinical studies to substantiate such claims by companies that sell needle goggles, this type of claim is no longer allowed to be made in the United States under the terms of a legal settlement with the Federal Trade Commission.
Occlusion holes, devices used by optometrists and ophthalmologists for the diagnosis of refractive errors, work on the same principle, but are not intended for use outside of diagnosis.
Video Pinhole glasses
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Source of the article : Wikipedia
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