Using overcorrecting minus glasses is a conservative treatment for exotropia. Prescription of the over minus glasses had different success rate and surgical therapy may lead to amblyopia and esotropia .therefore, we decided to fulfill a retrospective study about it

During a descriptive cross-sectional study all the patients under seven years old with Exotropia were included. The data gathered in a pre-designed forms include: Gender, Age, level of refraction (Cycloplegic Refraction), the amount of deviation before and after using the over minus glasses, visual acuity, the sphere of lens, the minus glasses therapy duration, recovery time span, and follow up time span .At the end of follow up, all data were collected in a check-list and were analyzed in SPSS software.

A total of 106 patients with an average age of 4.74±2.25 years were enrolled in this study. About 40 patients (38%) were male and remainders were female. The mean age of boys and girls were 2.22±0.35 and 2.28±0.28 years' old respectively. Average amount of exotropia before and after treatment was 20.96±8.20 and 12.16±11.04 prism diopter respectively. The mean refractive spherical and astigmatic error (cycloplegic refraction) obtained was respectively 1.34±1.07 and 0.32±0.72 diopter. At the end of the follow-up, only 6 patients had increased exotropia and 16 patients with average deviation 25.0±6.06 prism diopter did not alter and 84 patients (79.24%) were treated successfully

According to the results of this study, treatment of intermittent Exotropia by over correcting lenses can be a safe procedure and it does not produce any change in refraction