Optics: diseases — симптомы, диагностика и лечение

Farsightedness, or hypermetropia, is an optical feature of the eye in which rays of light are collected conventionally behind the retina, and not on it: the eye is too short or its refractive power is too weak. The name confuses people: with noticeable hypermetropia, it is difficult to see both near and far, but a young man with a slight plus can freely read the bottom lines of the table, paying for it with a headache in the evening. Another common confusion is with the word “age-related”: hypermetropia and presbyopia are designed in completely different ways, although both sooner or later lead to reading glasses. And the main thing you should know right away: glasses do not spoil vision and do not “wean the eyes from working,” but in a child, uncorrected farsightedness can actually lead to strabismus and a persistent decrease in vision, which is then no longer lifted by the glasses.

Astigmatism is a condition in which the refractive surfaces of the eye, most often the cornea, are not perfectly spherical: they bend more in one direction than in another. Because of this, the light is collected not into one point, but into two different focal lines, and the brain receives an image stretched in one direction: the point turns into a stroke, the round headlight into an elongated spot, and the letters “O” and “C” become indistinguishable. Almost everyone has a slight astigmatism, and it does not require any action, but starting from about 0.75-1.0 diopters it already noticeably reduces the quality of vision and causes headaches. Children's age is especially important: if a child with astigmatism sees a blurry picture for years, the visual cortex simply will not learn to process a clear image, and amblyopia will develop, which is very difficult to correct after 8-9 years.

Refractive errors are conditions in which the image is focused away from the retina and vision becomes blurry. These include myopia, farsightedness and astigmatism. These are not diseases of the eye in the usual sense, but features of its optics, and they are corrected with glasses, lenses or surgery. Childhood myopia deserves special attention: it progresses while the eye is growing, and modern ophthalmology can slow down this process - but only if it starts on time.