Ophthalmic decongestants are medications that provide temporary relief for redness, burning and minor irritation in the eyes. Ophthalmic decongestants reduce redness in the eyes by constricting dilated blood vessels. The effects of decongestants may last up to six hours.
Ophthalmic decongestants are a class of medications known as alpha agonists. Alpha agonist drugs stimulate the activity of protein molecules known as alpha adrenergic receptors on smooth muscles of blood vessels and make them contract. The constriction of eye’s blood vessels reduces redness and irritation in the eyes.
Some ophthalmic decongestant drugs are combined with a lubricant such as glycerin to prevent dryness and irritation, and/or zinc sulfate, an astringent that helps reduce redness and irritation in the eyes.