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Myopia generally appears before the age of 8, often becoming gradually worse until about the age of 20, when it ceases to change much. In later years the nearsighted person may find he or she can read comfortably without glasses. In children the most frequent symptoms of myopia are attempts to brush away blurriness, frequent rubbing of the eyes, and squinting at distant objects. Myopia can almost always be corrected with eyeglasses or contact lenses. Surgical procedures to correct it include radial keratotomy, photorefractive keratectomy, and lasik.
nearsightedness/near·sight·ed·ness/ (nēr-sīt´ed-nes) myopia.
nearsightednessMyopia, see there.
Synonym(s): nearsightedness, shortsightedness.
acquired myopia Myopia appearing after infancy, or in adulthood. Almost all myopias are acquired. Those myopias developing in the late teens and adulthood are usually referred to as late-onset myopia (or adult-onset myopia), whereas those occurring earlier are often referred to as early-onset myopia (or juvenile-onset myopia).
myopia control Term used to encompass the various methods aimed at slowing or arresting the progression of myopia. They include bifocals, contact lenses, pharmaceutical agents, incorrect single vision lenses (undercorrection, overcorrection), vision therapy and feedback strategies. None has yet been found to be reliably effective.
degenerative myopia See pathological myopia.
early-onset myopia See acquired myopia.
empty-field myopia See space myopia.
false myopia See spasm of accommodation.
form-deprivation myopia Myopia developing in children when the retina is stimulated by a blurred image during the critical period of development. It may occur as a result of a pathological condition, such as cataract, vitreous haemorrhage, ptosis, eyelid closure, or in inordinately long occlusion therapeutic sessions. See critical period; occlusion therapy.
high myopia Myopias above 6.0 D or more are usually considered as high myopias. See open-angle glaucoma; high index lens; pathological myopia.
hypertonic myopia See spasm of accommodation.
index myopia See lenticular myopia.
instrument myopia A temporary increase in accommodation induced by looking through an optical instrument. See resting state of accommodation.
juvenile-onset myopia; late-onset myopia See acquired myopia.
lenticular myopia Myopia attributed to an increase in the index of refraction of the lens. As a result there is an increase in refractive power. Such a change usually accompanies the development of some cataracts. This type of myopia may also accompany or follow an increase in blood sugar level, in which case it is usually of a transient nature, i.e. the power of the crystalline lens diminishes after the blood sugar level returns to normal. Syn. index myopia. See nuclear cataract; diabetes; micro-spherophakia.
low myopia Myopias of 3.0 D or less are usually considered as low myopias.
malignant myopia See pathological myopia.
medium myopia Myopias between 3.0 and 6.0 D are usually considered as medium myopias.
night myopia An increase in ocular refraction (essentially accommodation) occurring at low levels of illumination. See resting state of accommodation.
pathological myopia Myopia attributed to retinal and choroidal degeneration resulting from excessive elongation of the eye. The myopia usually exceeds 8-10 D, tends to increase rapidly during adolescence and continues to increase during adulthood. Visual acuity is usually subnormal after correction. Pathological myopia is a potential cause of blindness. Syn. degenerative myopia; malignant myopia; progressive myopia. See choroideremia; myopic crescent; macular hole; retinal detachment; sclerochoroiditis; Fuchs' spot; anterior staphyloma; vitreous detachment.
physiological myopia This is the most common type of myopia. It is believed that high myopia is due mainly to genetic factors whereas low myopia is more likely due to environmental influences. It occurs because of a failure in correlation of the refractive power of lens and cornea, and the length of the eye. Thus, the power of the eye is too great for its length. Unlike pathological myopia, this myopia usually stabilizes when the growth process has been completed. It is associated with normal visual acuity after correction. Syn. simple myopia; typical myopia.
progressive myopia See pathological myopia.
senile lenticular myopia See second sight.
simple myopia See physiological myopia.
space myopia An increase in accommodation occurring when viewing a field without any stimuli to accommodation as, for example, a clear sky. Syn. empty-field myopia. See resting state of accommodation.
spurious myopia See spasm of accommodation.
typical myopia See physiological myopia.
|Table M10 Approximate relationship between uncorrected myopia and visual acuity|
|Snellen visual acuity|
|Table M11 Common ocular and systemic diseases with myopia as an associated sign|
|Marfan's syndrome||retinopathy of prematurity|
|Ehlers-Danlos syndrome||Stargardt's disease|
|Cornelia de Lange syndrome||choroideraemia|
|Weil-Marchesani syndrome||gyrate atrophy|
|Laurence-Moon-Bardet- Biedl syndrome||rod monochromat|
|Riley-Day syndrome||ectopia lentis|
|Turner's syndrome||Fabry's disease|
|congenital stationary night blindness|
|Stickler's syndrome||Wagner's syndrome|
|pigment dispersion syndrome|
Synonym(s): nearsightedness, shortsightedness.
Patient discussion about nearsightedness
Q. Is there a laser vision correction operation that will correct both near and farsightedness? My optometrist said that typical laservision would require that I wear glasses for reading since it only corrects farsightedness. I'm leery of the technique of doing only one eye for distance and leaving the other "as is" for reading. I seem to recall a brief news report of some new laser vision technique that corrects both near- and farsightedness. Is that true or were they referring to the "one eye for closeup and one eye for distance" type of correction that I'm skeptical about? Thanks!!