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nearsightedness

(Encyclopedia)nearsightedness or myopia, defect of vision in which far objects appear blurred but near objects are seen clearly. Because the eyeball is too long or the refractive power of the eye's lens is too stro...

guide dog

(Encyclopedia)guide dog, a dog trained to lead a blind person. The first school for training such dogs was established by the German government after World War I for the benefit of blinded veterans. Schools now exi...

blindness

(Encyclopedia)blindness, partial or complete loss of sight. Blindness may be caused by injury, by lesions of the brain or optic nerve, by disease of the cornea or retina, by pathological changes originating in syst...

European Court of Human Rights

(Encyclopedia)European Court of Human Rights: see Council of Europe. ...

neurology

(Encyclopedia)neurology no͝orŏlˈəjē, nyo͝o– [key], study of the morphology, physiology, and pathology of the human nervous system. As researchers, neurologists carry on investigative and experimental work i...

stereoscope

(Encyclopedia)stereoscope stĕrˈēəskōpˌ [key], optical instrument that presents to a viewer two slightly differing pictures, one to each eye, to give the effect of depth. In normal vision the two eyes, being a...

Zaleucus

(Encyclopedia)Zaleucus zəlo͞oˈkəs [key], fl. c.650 b.c., Greek lawgiver of Locris, in Italy. According to tradition, his was the earliest codification of Greek law. References to Zaleucus' code, which was widel...

Zernike, Frits

(Encyclopedia)Zernike, Frits, 1888–1966, Dutch physicist, Ph.D. Univ. of Amsterdam, 1915. He was on the faculty at the Univ. of Groningen from 1915 until his retirement in 1958. Zernike received the 1953 Nobel Pr...

farsightedness

(Encyclopedia)farsightedness or hyperopia, condition in which far objects can be seen easily but there is difficulty in near vision. It is caused by a defect of refraction in which the image is focused behind the r...

night blindness

(Encyclopedia)night blindness, inability to see normally in subdued light. It is usually a result of vitamin A deficiency. The rod cells, one of two light-sensitive areas of the retina of the eye, are impaired in t...