Final answer:
Ptosis is the term used to describe drooping of the eyelid on one side. One possible cause of ptosis is myasthenia gravis, an autoimmune disorder affecting muscle strength.
Step-by-step explanation:
When a patient presents with complaints of drooping of the eyelid on one side, the finding is documented as ptosis. Ptosis can be caused by various reasons, including muscle weakness, nerve damage, or structural abnormalities. One condition that can cause ptosis is myasthenia gravis, an autoimmune disorder affecting muscle strength and function.