The principle of glasses for anisometropic eyes?

Abstract: both eyes are myopia. Monocular corrected visual acuity can reach more than 1.0 (5.0). When equipped with remote glasses, if diplopia does not appear in both eyes, it can be completely corrected. In case of diplopia, the degree of height eye shall be appropriately reduced (up to 2.50d). The low degree eye does not reduce the degree, and is completely corrected.

anisometropic eyes need special rules: not only special distance glasses, but also special proximity glasses.

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human eyes are unstable, easy to change and highly plastic in adolescence. They are the main period for the formation of anisometropia and the key period for controlling and reducing anisometropia. Therefore, in optometry, we should not only correct ametropia, improve vision and reduce visual fatigue, but also consider the direction of refractive development to prevent the occurrence and development of myopia, Gradually reduce the degree of hyperopia, control and reduce anisometropia, prevent the formation of alternating vision, strabismus and amblyopia, maintain and establish binocular vision and stereo vision, and improve visual quality. The different degrees of binocular refractive defects (errors) are called anisometropia. When the degree of anisometropia is greater than 2.50 degrees, after complete correction with ordinary frame glasses, the aberration caused by concave lens and convex lens may make the binocular vision worse than monocular vision, resulting in diplopia (people often say double shadow, double shadow and blur) and serious visual fatigue. Therefore, glasses for anisometropic eyes need special rules: not only special distance glasses, but also special proximity glasses.

prescription principle of distance glasses:

1. Both eyes are myopia. Monocular corrected visual acuity can reach more than 1.0 (5.0), If diplopia does not appear in both eyes when using remote glasses, it can be completely corrected. In case of diplopia, the degree of height eye shall be appropriately reduced (up to 2.50d). The low degree eye does not reduce the degree, and is completely corrected. Avoid diplopia and maintain a certain stereo vision, Normal eye position (prevent strabismus) and prevent the further development of high eye degree. If the maximum corrected visual acuity of high eye is less than 0.2, the high eye degree can be reduced to the same as that of low eye. Make the thickness and weight of left and right lenses equal, and wear beautiful and comfortable. If the anisometropia is too large and the stereoscopic vision is too poor, some work requiring accurate positioning cannot be completed (such as driving, playing ball, surgery…), contact lenses should be equipped. Or contact lenses should be equipped for high myopia to correct the myopia of anisometropia, and frame glasses should be used to correct the myopia of the rest of both eyes. Diplopia will also not occur. Good stereo vision will be restored.

2. One eye is short-sighted and the other eye is emmetropic (no refractive error). Myopia shall be corrected as much as possible to improve vision. As long as there is no diplopia, remote glasses shall be equipped to form good binocular vision, which is conducive to maintaining and establishing stereo vision and normal eye position, and preventing the formation of alternating vision and loss of stereo vision. If life and work require long-term close use of eyes, close use glasses shall be equipped in time to prevent the further expansion of anisometropia 。 Myopia with contact lenses can be completely corrected, with normal far and near vision and no diplopia.

  3. Myopia in one eye and hyperopia in the other. If the monocular corrected vision can reach more than 1.0, the hyperopia should be completely corrected when equipped with telephoto glasses, Myopia is appropriate (incomplete) correction. Make the binocular vision no less than monocular vision, prevent children from hyperopia, amblyopia and strabismus, and have normal stereoscopic vision, so as to avoid the formation of binocular alternating vision. If the corrected vision of hyperopia is less than 0.8, the binocular vision is no less than that of myopia after complete correction of both eyes, and it shall be completely corrected. If both eyes have formed alternating vision, it shall not be completely corrected to make myopia The eye is not developing.

  4. Both eyes are hyperopia. If the binocular corrected vision is close and the binocular vision is not lower than the monocular vision, it can be completely corrected. Otherwise, the correction degree of low-grade eyes should be increased (causing mild myopia), the vision of low-grade eyes should be reduced, and diplopia should be eliminated. If the corrected vision of high-grade eyes is significantly lower than that of low-grade eyes and lower than 0.2, the degree of high-grade glasses should be reduced by 2.50 degrees, so that the high-grade eyes do not work, and the degrees of both eyes are close, so as to make the remote-use glasses beautiful and comfortable.

  5. Look squarely and farsightedly. After complete correction of hyperopia, if the binocular vision is higher than the monocular vision, it shall be completely corrected. If binocular vision is lower than monocular vision, Hyperopia can not be corrected (low correction is not allowed to prevent visual fatigue); if the corrected visual acuity of hyperopia is higher than 0.8, it shall be completely corrected, and the emmetropia shall be added to make the emmetropia form mild myopia, and the binocular vision and stereovision shall be normal. Hyperopia shall be prevented from forming disuse amblyopia and strabismus.

6. Binocular astigmatism and anisometropia. Complete correction (exceptions in some cases).

prescription principle of proximity glasses:

I. binocular myopia: in order to prevent the further development of myopia, further expand anisometropia and reduce visual fatigue, add it down after complete correction of both eyes. If the low-grade eye is less than 1.5 degrees, it can be added down without equivalent.

II. Binocular hyperopia: add equivalent after complete correction. If one eye has poor eyesight, as long as there is light perception, it should also be added normally to prevent visual fatigue and symptoms.

III. one eye emmetropia and one eye myopia: unequal addition after complete correction. For example, when reading and writing, myopia can be increased by 2.50 degrees and 1.00 degrees can prevent the development of myopia and the expansion of anisometropia.

IV. one eye squarely and one eye hyperopia: unequal addition after complete correction. (hyperopia should be added normally as long as there is light perception) add 1.50 degrees to reduce visual fatigue. Hyperopia does not need to be added to prevent the expansion of anisometropia.

v. one eye of myopia and one eye of hyperopia: it is not added after complete correction. (hyperopia should be added normally as long as there is light perception) myopia should be added 2.50 degrees at present, and hyperopia should be added a small amount to prevent the development of myopia and the expansion of anisometropia.

Vi. binocular astigmatism: binocular myopia astigmatism, binocular hyperopia astigmatism and binocular mixed astigmatism are added after complete correction. One myopia astigmatism and one hyperopia astigmatism are added after complete correction.

VII. Other cases: add it if it is not equivalent after complete correction.