Mechanical ptosis is caused by an increased weight on or obstruction to elevation of the upper eyelid due to an eyelid or conjucntival mass, scar, redundant eyelid skin, fat, or infection. Despite the ptotic position of the eyelid, the levator muscle and nerve supply are typically normal. Treatment is first directed at the obstructing mass or scar which in the majority of cases will lead to resolution of the apparent ptosis. If the ptosis persists or fails to improve sufficiently, the original condition may have infiltrated the levator muscle or may have induced a traumatic disinsertion of the levator aponeurosis. In such cases, reinsertion of the aponeurosis may be required.