Lumigan (bimatoprost ophthalmic solution) is a synthetic prostamide analog with ocular hypotensive activity that works by regulating the flow of fluid within the eye to maintain a normal pressure used to treat certain types of glaucoma and other causes of high pressure inside the eye. Lumigan is also used to improve fullness, length, and color of the eyelashes in people with a condition called hypotrichosis, a lack of eyelash growth.