Lumigan Coupon is a brand name for an eye drop solution that contains the active ingredient bimatoprost. Bimatoprost is a prostaglandin analog used primarily to treat glaucoma and ocular hypertension by reducing intraocular pressure. It is believed to work by increasing the drainage of aqueous humor (fluid within the eye), thereby lowering intraocular pressure. In addition to its use for treating glaucoma and ocular hypertension, bimatoprost, the active ingredient in Lumigan, has been found to have a side effect of promoting the growth of eyelashes. Due to this side effect, bimatoprost-based products like Lumigan and Careprost (as mentioned in the previous response) have been used for cosmetic purposes to enhance eyelash growth.