Ptosis is the medical term for drooping of the upper eyelid. When the upper eyelid margin is lowered to cover the pupil, it may cause a reduction in the field of vision. This may be due to a muscle or nerve weakness.  Patients with ptosis can have difficulty keeping their eyelids open. and will often raise their eyebrows to compensate for their drooping eyelids. In severe cases, people with ptosis may need to lift their eyelids with their fingers in order to see. Children with ptosis may develop amblyopia (“lazy eye”) or developmental delay from limitation of their vision.Ptosis can be corrected surgically and usually involves tightening the levator muscle to elevate the eyelid. Often in congenital ptosis, the levator muscle is extremely weak.  A “sling” operation can be performed, to enable the forehead muscles to elevate the eyelid(s). For some cases with small amounts of ptosis, surgery on the muscle on the inside of the lid may be performed.