This study aims to compare the short-term effect of oxymetazoline 0.1% (Upneeq) versus brimonidine 0.025% (Lumify) on upper-eyelid position in adults with acquired ptosis. Participants will undergo standardized eyelid photography, receive a single dose of either Upneeq or Lumify in randomized order, and have repeat photographs approximately 60 minutes later. They will return for a second visit to receive the alternate medication using the same procedures. Eyelid height measurements will be obtained from coded images by masked graders. Data will be analyzed using paired statistical methods appropriate for a crossover design. Both medications are FDA-approved topical ophthalmic drops, and the study involves minimal risk with anticipated transient ocular irritation as the most common adverse event.

Inclusion Criteria:

• Adults age ≥18 years
• Acquired ptosis with MRD1 ≤ 2.5 mm in at least one eye
• Ability to complete both study visits (≥48 hours apart)
• Fluent in English
• Able to provide informed consent

Exclusion Criteria:

• Congenital ptosis or mechanical ptosis due to mass effect
• Ocular surgery within the past 6 months
• Significant active ocular surface disease
• Current contact lens wear on study days
• Known allergy to oxymetazoline or brimonidine
• Use of MAO inhibitors, α-blockers, or contraindicated medications
• Pregnancy or lactation
• Significant uncontrolled cardiovascular disease
• Any condition that may interfere with study procedures or data reliability