Naphazoline
Naphazoline is an imidazole derivative and a direct-acting sympathomimetic amine with vasoconstrictive activity. Upon ocular administration, naphazoline exerts its effect by acting on alpha-adrenergic receptors in the arterioles of the conjunctiva to produce vasoconstriction, resulting in decreased conjunctival congestion and diminished itching, irritation and redness.