Careprost, a kind of bimatoprost, is found in the eye drops. Intraocular pressure is reduced with this ingredient, which is why it is often used to treat glaucoma. A side effect of the ophthalmic serum used to treat elevated intraocular pressure was the development of thicker eyelashes. Since then, people have been using Careprost Eyelash Serum 0.03% to promote thicker, longer, and darker lashes.