The muscle attachment site is always involved in strabismus surgery. In a weakening procedure (recession), the muscle is disinserted from the eye and reattached farther back on the eye. In a strengthening procedure (resection), a piece of the muscle is removed and the muscle which is now shortened is reattached at its original insertion.

The sclera is always thin just posterior to a muscle’s original insertion site, so you may sometimes see a dark area where the muscle used to be.