周囲の明暗と瞬間中心視力

Surrounding dark and light, and instantaneous central visual acuity

1．緒言

　古来，視力と時間に関する実論報告は極めて狭い範囲に限られている．高氏は同調応で，大山氏は一定照度に調応して視標輝度を変え，私は暗調応眼で実験して，夫々異つた結果を得ている。私は此の間の推移を知ろうとして室内照度を変えて実験を行つたので茲に報告する。

We investigated the influence of surrounding dark and light for central visual acuity. Illumination of index mark 160rL, constant. Black, Landolt's ring, White back,10cm angle. White Landolt's ring black back.Exposure time 2~400ms. Sarrounding illumination : 250L, 50L, 10L, and dark (reflex rate 60%), Experimentalperiod : 40days.

1) Usually, white L.'S ring with black back was more clearly seen tham black L'sring.

2) When the illumination of the room was similar to the one of index mark, visnal acuity increased in proportion to the exposuretime.