Background:

Naphazoline hydrochloride is an ocular vasoconstrictor and imidazoline derivative sympathomimetic amine.Target: Adrenergic ReceptorNaphazoline hydrochloride is the common name for 2-(1-naphthylmethyl)-2-imidazoline hydrochloride. It is a sympathomimetic agent with marked alpha adrenergic activity. It is a vasoconstrictor with a rapid action in reducing swelling when applied to mucous membrane. It acts on alpha-receptors in the arterioles of the conjunctiva to produce constriction, resulting in decreased congestion. It is an active ingredient in several over-the-counter formulations including Clear Eyes and Naphcon eye drops. From Wikipedia.

参考文献:
[1]. http://en.wikipedia.org/wiki/Naphazoline