What term describes the drooping of the upper eyelid?

The term that describes the drooping of the upper eyelid is ptosis. This condition can occur due to various reasons, including muscle weakness, nerve damage, or age-related changes. The levator palpebrae superioris muscle is primarily responsible for lifting the eyelid, and if this muscle is impaired or weakened, ptosis can result. It can affect one or both eyelids and may vary in severity.

Other conditions mentioned, such as entropion, refer to the inward turning of the eyelid, strabismus involves misalignment of the eyes, and nystagmus is characterized by involuntary eye movements. While each of these terms relates to different eye conditions, ptosis specifically targets the position and function of the upper eyelid.