The ophthalmic solution for Careprost eye drops may cause an increase in iris pigmentation, which could result in a change in iris color. Use this medication carefully and only under your doctor's supervision as directed since the brown pigmentation surrounding the pupil may spread and these are some of the symptoms that may develop. Avoid using other medications at the same time as Bimatoprost without first consulting your doctor since doing so may result in interactions. Informing your doctor about all of your medications, both prescription and over-the-counter, is recommended. In the event that the bottle is broken or otherwise damaged, do not use this suspension. If you are nursing a baby or are pregnant, speak with your doctor.