Purpose : This study described the subjects with the range of around 45 years old who start to show a lowered flexibility in their lens due to aging. We carried out stereoacuity test and research for the influence on visual acuity wi th distance for prescribing for monovision. Methods : The researchers prescribed monavision for 100 male and female adults who were wearing glasses for near vision or progressive addition lens due to presbyopia and had been resided around Ulsan and Daejeon for the period of Septernber to October. 2008. Also the researchers gave prescription for distance vision on the dominant eye and for near vision on the non-dominant eye through visual acuity test regarding near and distance vision and eye dominance test. For near stereoacuity test. we used the Stereo Fly Test. Results : After prescribing for monovision. all eyes showed reduction m stereoacuity. distance vision and near vision also deerease in binocular. Conclusions : We judged that have to be cautions with problems induced by deerease of stereoacuity and visual acuity in prescription for presbyopia correction.