In these days, many VDT workers and young people have binocular stereopsis imperfection. Especially young people who keep the viewpoint to nearness for a long time may be damaged to the growth of stereoscopic ability. 
The purpose of this study is to elucidate the mechanism of stereopsis imperfection focusing on cooperation between binocular stereoscopic vision and motion, binocular convergence and accommodation, and to develop methods to restore binocular stereoscopic function.