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

交替性内手术采用同等量内直肌后徙术，不但手术成功率高，而且有利于手术后双眼三级功能的建立。

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

目的探讨间歇性外佳手术时机，以求达到矫正并获得完善的双眼单功能目的。