ランタンテストによる先天色覚異常の評価

Evaluation of congenital defective color vision by lantern test

　先天赤緑異常3,297例の市川ランタンの成績を検討した。検査光9組の誤数の平均は第1色盲は7.8，第2色盲は6.1，第1色弱は5.4，第2色弱は4.9で有意の差があった。試行2回の誤数の差1以内のものは，第1色盲は86％，第2色盲は82％，第1色弱は88％，第2色弱は83％で，高い再現性を示した。ランタンテストをパスするもの（誤数0）は1.9％，そのうち2回以上の試行で常に正答であったものは約1／3（0.6％）で，色光視認は色覚異常者にとって非常に難しい。

　ランタンテストは，信号灯とは一線を画して，堅固な理論的根拠を持つ色覚検査とすべきである。

Ichikawa's lantern test was performed in 3,297 persons with congenital red-green defect. They were classified by anomaloscope into 4 groups: protanopia, deuteranopia, protanomaly and deuteranomaly. The mean scores of lantern test were: 7.8 in protanopia, 6.1 in deuteranopia, 5.4 in protanomalous tri-chromatism and 4.9 in deuteranomalous trichromatism. Each of the 4 groups could be sharply divided from others. Out of the whole series, 63 persons showed passing scores, meaning no errors on the one trial at least, and only one-third of them could name the colors always correctly. This finding seemed to show that color-defective persons, however mild, would find difficulty in recognizing colored lights. More than 80% of test subjects showed the same scores or scores different only by one on two consecutive trials, implying the sufficient reliability of the test.