In strabismus patients, when should surgery be performed? Generally speaking, surgery is an option when the strabismus is large and obvious in appearance, accompanied by symptoms of diplopia and vision loss or when it seriously affects the visual function of both eyes. What is the best age to operate on my child’s strabismus? The development of strabismus can affect the child’s binocular vision and cause loss of stereo vision. Early surgery can not only save the visual function, but also restore the lost visual function as soon as possible.