What is the cap color of cholinergic agonists used in glaucoma medications?

• A. Green
• B. Dark blue
• C. Mint green
• D. Orange

Answer: (A)

Color coding in glaucoma eye drops helps identify the drug class at a glance, and green caps are used to signal cholinergic agonists (miotics). Pilocarpine, a classic cholinergic agonist, is a typical example and often comes with a green cap to indicate its class. This visual cue helps clinicians and patients avoid mix-ups when multiple eye drops look alike. Pharmacologically, cholinergic agonists stimulate muscarinic receptors, causing the iris sphincter and ciliary muscle to contract, leading to pupil constriction (miosis) and improved outflow through the trabecular meshwork, which lowers intraocular pressure. So green is the cap color associated with these miotic agents.