In severe cases, ptosis may be present at birth and, if left untreated, can permanently damage vision by forcing the unaffected eye to do all the work while letting the affected eye degenerate. The tendon of the levator muscle may loosen or detach, causing ptosis. This process is similar to a knee ligament sprain or tear. Levator dehiscence occurs primarily in people greater than thirty years of age and the incidence increases with age. It is not uncommon for one to develop a droopy upper eyelid following cataract surgery.
Congenital ptosis is the common form of eyelid ptosis present since childbirth.
It may involve one or both upper eyelids and vary in severity from mild to severe. This form of eyelid ptosis is often the result of lack of development of the levator muscle. The surgery may also use other methods to repair the ptosis, such as a technique called fascia suspension. The drooping eyelid is the principal sign in ptosis. Children with congenital ptosis often tilt their heads back or raise their eyebrows to lift the eyelid.