Amaurosis - black cataract

A general term for a condition in which vision is reduced and vision is impaired even though there is no abnormality inside the eye, including the fundus. In the past, amaurosis was used to refer to a condition in which the pupil is clear and light is not reflected, resulting in black vision and reduced vision, as opposed to cataracts, in which the inside of the pupil becomes cloudy, and glaucoma, in which the inside of the eye appears blue when viewed through the pupil during an attack. In other words, in the past, diseases of the retina or optic nerve with unclear findings were called amaurosis, but now the findings are clearly known and each disease has its own name. Diseases that are still called amaurosis include hysterical amaurosis, transient amaurosis, in which vision is temporarily lost during a transient ischemic attack, and nephritic amaurosis, in which blindness occurs due to central brain damage during renal hypertension.

[Mizuo Matsui]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

眼底を含め眼内に異常がないのに視力が低下して見えなくなる状態の総称。かつては瞳孔(どうこう)（ひとみ）の中が白く濁ってくる白内障（白そこひ）や発作のときに瞳孔を通して眼内を見ると青く見える緑内障（青そこひ）に対し、瞳孔の中に濁りがなく、光が反射してこないために黒く見え、しかも視力が低下してくる状態を黒内障（黒そこひ）とよんでいた。つまり、古くは網膜や視神経の病気で所見のはっきりしないものを黒ぞこひとよんでいたが、現在では所見がはっきりわかり、それぞれ病名がつけられている。現在でも黒内障という病名が使われているものには、ヒステリー性黒内障をはじめ、一過性脳虚血発作のときに一時的に見えなくなる一過性黒内障、腎性(じんせい)高血圧のときに大脳の中枢障害によって失明症状がみられる腎炎性黒内障などがある。

［松井瑞夫］

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