Which eye drop has a red cap and lasts about 1-2 days?

Which eye drop has a red cap and lasts about 1-2 days?

• A. Homatropine
• B. Phenylephrine
• C. Tropicamide
• D. Cyclopentolate

Answer: (A)

Homatropine is a cycloplegic antimuscarinic, meaning it paralyzes the ciliary muscle and dilates the pupil. It has a relatively long duration among common ophthalmic drops, typically about 24 to 48 hours, which matches the description of lasting about 1–2 days. In many practice settings, this drop is color-coded with a red cap, reflecting its longer-acting cycloplegic effect. The other agents differ: phenylephrine is mainly a pure mydriatic with little to no cycloplegia and a shorter duration; tropicamide provides quick dilation but lasts only a few hours; cyclopentolate offers longer-lasting dilation than tropicamide, often around a day, but not as consistently in the 1–2 day range as homatropine.

Homatropine is a cycloplegic antimuscarinic, meaning it paralyzes the ciliary muscle and dilates the pupil. It has a relatively long duration among common ophthalmic drops, typically about 24 to 48 hours, which matches the description of lasting about 1–2 days. In many practice settings, this drop is color-coded with a red cap, reflecting its longer-acting cycloplegic effect. The other agents differ: phenylephrine is mainly a pure mydriatic with little to no cycloplegia and a shorter duration; tropicamide provides quick dilation but lasts only a few hours; cyclopentolate offers longer-lasting dilation than tropicamide, often around a day, but not as consistently in the 1–2 day range as homatropine.