Methods The optometer is composed of singlechip, handle and LCD.The eyesight is examined by selecting exposure of random sample eye-chart mark E within direction keys on the handle.

采用微计算机控检测仪，其由单片机、手和液晶显示屏构，手具有下左右方向等功能键，根据手按键选取随机出现标"E"朝向正确与否来检测。