To begin with, surgery can't improve the level of vision or glass power and lazy eye, so glasses and patching are still needed following the surgery. The operation usually weakens or strengthens the muscles of the eye, so that the eyes are better aligned. Post-surgery there is improvement in depth perception (stereopsis), binocularity, and field of vision which is limited in the presence of a squint as the brain does not use both eyes together.
If the child has cylindrical power/ astigmatism, there may be a slight change in the power post-surgery as the eyes are aligned straight. The glass power is re-checked 4 weeks or as and when inflammation in the eye goes away after dilation (cycloplegic refraction) to rule out a change in glass power.
However, if glasses have a prism in them before surgery, then glasses without a prism should be acquired for use immediately after. Contact lenses are generally not comfortable for approximately two weeks following the procedures.
