<unk> (ophthalmic) is an alpha-1 adrenergic receptor agonist that is FDA approved for the procedure of to dilate the pupil.   Common adverse reactions include pain in eye, transient, ophthalmic solution.
Phenylephrine 
Methylergonovine 
Prazosin
Terazosin
Doxazosin
Trimazosin
Oxymetazoline
Tramazoline