Where To Buy Careprost? Careprost functions by increasing the natural flow of tear fluid out of the eye, thereby reducing intraocular pressure. Bimatoprost ophthalmic, the active ingredient, is a member of the class of drugs known as prostaglandin analogs. Controlling eye pressure can help treat some forms of glaucoma and prevent blindness. The drug may also be used by some people to lengthen and thicken their eyelashes.