Objective To study the optimal time for operation of intermittent exotropia, so that we can orthopia strabismus and attain normal binocular function.

目探讨间歇性外斜最佳手术时机，以求达到矫正斜得完善双眼单目。

Conclusion:Symmetric recession of internus in alternative esotropia can improve the success rate and the binocular vision function.

交替性内斜手术采用同等量内直肌后徙术，不但手术成率高，而且有利于手术后双眼三级建立。