Clinical features of congenital internal strabismus: 1, within six months of the onset of internal strabismus 2, large angle of internal strabismus 3, inadequate eye movement outward 4, cross gaze or alternate gaze 5, with DVD inferior oblique muscle function is too strong 6, nystagmus Treatment of congenital internal strabismus 1, dilated pupil examination without significant hyperopic internal strabismus surgical correction 2, cover the key eye so that both eyes can alternate gaze 3, surgery (1) timing The age of surgery at about one year (2) purpose Internal strabismus reduced to within 10 trigeminal