nearsightedness
91astigmatism — /euh stig meuh tiz euhm/, n. 1. Also called astigmia /euh stig mee euh/. Ophthalm. a refractive error of the eye in which parallel rays of light from an external source do not converge on a single focal point on the retina. 2. Optics. an… …
92contact lens — one of a pair of small plastic disks that are held in place over the cornea by surface tension and correct vision defects inconspicuously. Cf. hard lens, intraocular lens, soft lens. [1885 90] * * * Thin artificial lens worn on the surface of the …
93cryolathe — /kruy euh laydh /, n., v., cryolathed, cryolathing. Ophthalm. n. 1. an instrument for reshaping the cornea to correct severe nearsightedness or farsightedness: the cornea is removed from the eye, rapidly frozen, reshaped, and reinserted. v.i. 2.… …
94eyeball — eyeballer, n. /uy bawl /, n. 1. the ball or globe of the eye. v.t. 2. Informal. to look at, check, or observe closely: two opponents eyeballing each other. [1580 90; 1900 05 for def. 2; EYE + BALL1] * * * ▪ anatomy spheroidal structure… …
95monovision lenses — Ophthalm. contact lenses that adjust one eye for farsightedness and the other for nearsightedness, used as an alternative to bifocal lenses. * * * …
96multifocal — /mul tee foh keuhl, mul tuy /, adj. 1. having several focuses. 2. (of an eyeglass lens) having several focusing areas that correct for both nearsightedness and farsightedness. [1915 20; MULTI + FOCAL] * * * …
97nearsighted — nearsightedly, adv. nearsightedness, n. /near suy tid, suy /, adj. 1. seeing distinctly at a short distance only; myopic. 2. shortsighted. [1680 90; NEAR + SIGHT + ED3] * * * …
98night blindness — nightblind, adj. Ophthalm. a condition of the eyes in which vision is normal in daylight but abnormally poor at night or in a dim light; nyctalopia. [1745 55] * * * ▪ physiology also called nyctalopia failure of the eye to adapt promptly …
99strabismus — strabismal, strabismic, strabismical, adj. strabismally, adv. /streuh biz meuhs/, n. Ophthalm. a disorder of vision due to a deviation from normal orientation of one or both eyes so that both cannot be directed at the same object at the same… …
100Donders, Frans Cornelis — born May 27, 1818, Tilburg, Neth. died March 24, 1889, Utrecht Dutch ophthalmologist. His study of muscae volitantes (spots before the eyes) resulted in Donders law, stating that the rotation of the eye around the line of sight is involuntary.… …
