A smart myopia prevention device based on 89C51 MCU is presented on the basis of comparison of current myopia prevention devices.This device has characteristic feature of multi-direction

user-friendly and easy to use.The device can effectively prevent short-signedness aimed at three main factors.The method in detail that measuring the distance between eyes and objects by ultrasonic is described.olar cell measurements to determine the intensity of light is used.MCU timers to calculate time by the duration of the eyes is used.Voice alert is used to achieve the purpose of prevention of short-sight.