Ptosis is an abnormally low position (drooping) of the upper eyelid. Ptosis occurs when the muscles that raise the eyelid (levator and Müller’s muscles) are not strong enough to do so perfectly. It can affect one eye or both eyes and occurs more frequently in the elderly, as muscles in the eyelids might possibly begin to deteriorate. 

The drooping might possibly be worse after being awake longer, when the individual’s muscles are tired. This condition is often called “lazy eye”, but that term normally refers to amblyopia. If severe enough and left untreated, the drooping eyelid can cause other conditions, such as amblyopia or astigmatism. This is why it is especially important for this disorder to be treated in children at a young age, before it can interfere with vision development. 

There are two ‘main’ surgeries that might possibly be performed on the upper eyelid. This section addresses Ptosis  which is the medical term for drooping of the upper eyelid; it might possibly affect one or both eyes. The other surgery of the upper eyelid addresses excess skin  is repaired by blepharoplasty.