Pinhole glasses

With a Pinhole glasses (also: hole glasses or goggles grid ) are not optically active glasses, but black plastic discs used in the form of a grid pattern ( " grid " ) are pierced with tiny holes. It has no corrective refractive effect, but may be similar to the effect of a narrow pinhole in some cases result in a sharper image due to the limitation of incidence of light on the principle of stenopaic gap. However, this improvement in visual acuity has at most diagnostic or experimental in nature and is in daily life more or less of no practical use, liberty of the possible subjective impression of each individual.

Types of grid Glasses

It offers the following types of raster Eyeglasses:

  • -Over Grid ( through holes )
  • With a square grid (square -outs ),
  • With pyramidal grid ( in curved glass pyramid-shaped holes arranged )
  • With " bifocal " grid ( different hole sizes).

The value and impact

The manufacturers and proponents of grid eyeglasses writing them to the following benefits, which will be built by her wearing:

  • Optical refractive errors such as nearsightedness or farsightedness should be able to be " trained away "
  • Visual acuity when looking through the small holes should be significantly improved
  • The extraocular muscles to be strengthened through the necessary sakkadierten movements,
  • There are positive effects on eye diseases such as glaucoma or cataracts be able to identify
  • The pinhole glasses is suitable as sunglasses especially for people who need a full range of sunglasses, because it is transparent to UV radiation.

Criticism

To date, no scientific proof has been furnished that the wearing of pinhole glasses on the objective degree of ametropia, ie the degree of nearsightedness or farsightedness, positive effect.

Looking through the small openings in the sharpness of the actual image may increase. This phenomenon is based on the principle of stenopaic gap and is caused by the elimination of interfering edge rays (spherical aberration). One effect is to increase the depth of field, similar to the effect of a pinhole in a camera that makes you look in ophthalmologic diagnostics advantage. Overall, however, the so-obtained temporary improvement in visual acuity in daily life is associated with very little practical use, there is still a major limitation of the visual field, which is associated with significant deficits in terms of a safe orientation in the outer space. Therefore both critics and manufacturers and distributors even advise strictly from having to wear glasses at grid activities for which a responsive and high-quality visual perception is needed, such as when driving or handling machinery.

The eye muscles are the most active by far the muscle group in human body. This is due not least to the fact that they need to perform permanent smallest movements ( saccades ) to counteract the phenomenon of local adaptation. This occurs with an average frequency of 1-3 cycles per second. Therefore an enforced through a hole grid sakkadenförmige movement for "training " of the eye muscles already appears completely useless. A Demonstration of a positive effect on the performance of the musculoskeletal system is also not yet provided.

A therapeutic effect on other eye diseases has been also not been established. The part of the manufacturers cited advantage of the transmittance of UV light is being described by critics as a disadvantage, since any UV light is harmful to the eyes. Therefore normal sunglasses protect against UV radiation almost completely. Another disadvantage of the glasses is in the solid height limitation of the visual field, as well as the reduction of the brightness and consequently the contrast.

Risks

The Inaussichtstellung an effective therapeutic influence on serious eye conditions can be assessed as gross negligence and entails the risk of long-term damage, for example by any delay in necessary treatment in gray or glaucoma. Therefore eye doctors strongly recommend against wearing a pinhole glasses as a permanent benefit is not apparent damage but very well seem possible.

Building a Pinhole glasses carries a risk for decompensation of latent strabismus in itself, since the very small holes in the so-called fusion is complicated and compromised, which is necessary for the maintenance of binocular single vision. This can result in latent squint persons result in noticeable strabismus with perception of double images.

Eye movement (sensory) Microsaccade Field of view William Bates (physician)
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