自操作式视力测定仪

A self-operative optometer

本文介绍一种自操作式视力测定仪。在标准视力表面每一视标下方安装发光二极管,通过发光二极管的发光与否来指定某一视标供受检者判别。受检者通过键盘输入自己对视标开口方向的判别。判别信号的鉴别,视标换行及同一行视标的随机选择由数字电路实现。所测定的视力由数码管显示。经试用与人工视力检查对照,相关系数R=0.87(P<0.001)。

This paper introduces a self-operative optometer. A LED is fixed under every optometrical symbol of standard test chart. According to whether it illuminates or not, an optometrical symbol is offered to examinee for verdict. The examinee inputs his or her verdict about orientation with keyboard. The discernment of verdict information on optometrical symbols, the jump of optometrical symbol from one line to another, and random selection of optometrical symbol on same line, are accomplished with digital circuit. The visual acuity determined is displayed by nixie tube. By comparison of trial use in 80 eyes of examinees with artificial examination, the coefficient of correlation R=0.81 (P<0.001).