refractive error

refractive error

[rifrak′tiv]

a defect in the ability of the lens of the eye to focus an image accurately, as occurs in nearsightedness and farsightedness.

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refractive

capacity to refract light.

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refractive error

a difference between the focal length of the cornea and lens, and the length of the eye, resulting in myopia or hyperopia.

refractive media

of the eye include the vitreous humor and the lens.

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refractive error 

The dioptric power (K) of the ametropia of the eye. It is equal to 1/k in dioptres, where k is the distance between the far point and either the spectacle plane (spectacle refraction), or the principal point of the eye, or the refracting surface of the reduced eye (ocular refraction), in metres. Thus

K = 1/k

when the eye is situated in air. Syn. ametropia (although this is not strictly so as ametropia is the anomaly); refraction of the eye; refractive status; static refraction. See far point of accommodation; Scheiner's experiment.

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refractive error

Ametropia, myopic shift Ophthalmology The inability of images to focus properly on the retina, often corrected by glasses contact lenses, or refractive surgery. See Astigmatism, Farsightedness, Myopia, Presbyopia.