Ptosis is a drooping upper eyelid that may partly cover the pupil. It can affect one or both eyes.
Common and benign causes
Ageing often weakens the lid muscle tendon, causing gradual droop. Long-term contact lens wear can also stretch the tissues.
- Involutional age-related ptosis with slow progression
- Mechanical droop from heavy lids or skin
- Congenital ptosis present from birth
- Previous eyelid surgery altering tendon position
Serious causes needing prompt review
Sudden ptosis can indicate nerve or muscle disease. Associated symptoms help identify urgency.
- Third nerve palsy with double vision and eye movement problems
- Horner syndrome with small pupil and reduced sweating
- Myasthenia gravis causing variable droop and fatigue
- Rapid-onset ptosis always warrants urgent assessment
