What does ptosis mean?
Ptosis is the medical term for an upper eyelid that droops below its normal position. It can affect one or both eyes and may occur at birth, develop with age, or result from nerve or muscle dysfunction. The condition is especially noticeable when the eyelid covers part of the pupil, because this can create an uneven appearance and sometimes obstruct vision. In clinical descriptions, ptosis may be classified according to its cause, including congenital, aponeurotic, myogenic, and neurogenic forms. The word is also encountered in phrases such as “ptosis of the eyelid.” While “droopy eyelid” is more familiar in general conversation, ptosis is the appropriate term in medical and ophthalmological contexts.
nounDrooping of the upper eyelid, in which the margin of the eyelid falls below its normal position over the eyeball. The condition may be congenital or result from weakness of the muscles that elevate the eyelid or from nerve damage.
- The abnormal drooping or falling of the upper eyelid.
"The ophthalmologist diagnosed ptosis affecting the patient's left eye."
"Ptosis can make one eye appear smaller and may partly obstruct vision."
"The surgeon said that the ptosis could be corrected surgically."
The plural is rarely needed in general writing but is standard in medical literature.
"The surgeon reviewed several cases of congenital ptoses."
Ptosis takes its name from the Greek word for “falling,” fittingly describing the characteristic downward droop of the upper eyelid.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does ptosis come from?
Ptosis comes from Greek ptōsis, meaning “a falling” or “a sinking,” and is derived from the verb piptein, “to fall.” The Greek word was adopted into medical terminology for the falling or drooping of the upper eyelid. Its sense reflects the same broader idea of downward movement found in modern words such as collapse, although those are not direct cognates in English.
How ptosis is actually used
This is a medical term, used mainly in ophthalmology and clinical writing. The general lay expression is “droopy eyelid” or “eyelid droop.” It should not be used to describe ordinary, temporary tiredness of the eyelids.