Part of our complete guide to Ptosis (Droopy Eyelid) — this page covers acquired (age-related) ptosis in depth.
Acquired Ptosis
Most adult ptosis is aponeurotic — the levator muscle is intact and still strong, but the fibrous aponeurosis (tendon) that transmits the muscle’s pull to the tarsus has stretched, thinned, or detached. The lid sits low not because of muscle weakness but because the mechanical connection is lost.
Common Causes
Aging: the most common cause by far — the aponeurosis disinserts from the tarsus gradually over decades. Levator function typically remains excellent (≥ 10 mm)
Long-term contact lens wear: repeated mechanical trauma from lens insertion and removal stretches the aponeurosis; a common cause in younger adults
Prior intraocular surgery: lid speculum use during cataract surgery is a well-recognized precipitant
Chronic eye rubbing or inflammation: repeated lid traction weakens the aponeurosis over time
Myasthenia gravis: a neuromuscular disorder producing variable, fatigable ptosis that characteristically worsens as the day progresses — must be excluded before planning surgery
Third nerve (CN III) palsy: can cause ptosis (often marked) and impaired eye movements; when the pupil is dilated and poorly reactive (pupil-involving form), it is a neurological emergency requiring urgent imaging, though pupil-sparing forms also occur
Clinical Examples
Examples of acquired ptosis — note the low upper-eyelid margin and the raised (high) eyelid crease.
Low lid margin with a high eyelid crease, both sides — involutional (aponeurotic) ptosisBoth upper lids droop, partly covering the eyesBoth sides, left lower than right (asymmetric ptosis)Both upper lids low in an older adult — low margin, high crease
Treatment of Acquired Ptosis
Because the levator muscle itself is usually strong in aponeurotic ptosis, repair simply re-attaches or tightens its stretched tendon. The approach is guided by the phenylephrine response:
External — levator advancement: through a hidden upper-lid-crease incision, the levator aponeurosis is re-secured to the tarsus. The most common and versatile repair, and the one that allows excess skin to be removed at the same time. Learn more →
Internal — Müller’s muscle–conjunctival resection (MMCR): done from the back of the lid with no skin incision; ideal for mild ptosis with a positive phenylephrine test. Learn more →
Upneeq® drops: a once-daily, non-surgical, temporary lift (typically about 1 mm, up to ~2 mm) for mild cases or patients avoiding surgery. Learn more →
Important: new-onset unilateral ptosis with a dilated, unreactive pupil requires same-day neurological evaluation to exclude cerebral aneurysm or transtentorial herniation.
Frequently Asked Questions
What is the most common cause of a droopy eyelid in adults?
Aponeurotic (involutional) ptosis — the levator muscle's tendon stretches or detaches with age, contact-lens wear, or after eye surgery, letting the lid drift down while the muscle still works.
Can acquired ptosis come on suddenly?
A sudden droop — especially with double vision, a large or small pupil, or pain — needs urgent evaluation, as it can signal a nerve (third-nerve palsy), Horner's syndrome, or myasthenia gravis.
