What is defined as a drooping of the upper eyelid?

The term that refers to drooping of the upper eyelid is ptosis. This condition can result from various causes, including muscle weakness, nerve damage, or certain medical conditions. Ptosis can significantly impact a person's vision and appearance, often requiring medical assessment to determine the underlying cause and appropriate treatment.

Blepharospasm, on the other hand, refers to involuntary blinking or spasm of the eyelids, which is not related to the drooping of the eyelid. Dacryocystitis involves inflammation of the tear sac, typically due to infection, and it primarily concerns the tear drainage system rather than eyelid position. Astigmatism is an optical condition caused by the irregular shape of the eye, affecting vision clarity but not related to eyelid structure or position. Understanding these distinctions helps clarify why ptosis is specifically defined as drooping of the upper eyelid.