Bimatoprost eye drops are a prescription medication primarily used to treat glaucoma and ocular hypertension, conditions characterized by increased pressure inside the eye that can damage the optic nerve and lead to vision loss. Bimatoprost belongs to a class of drugs called prostaglandin analogs. It works by increasing the outflow of aqueous humor, the fluid in the eye, thereby reducing intraocular pressure.

A notable side effect of bimatoprost is its ability to enhance eyelash growth. This led to the development and approval of a specific formulation for treating eyelash hypotrichosis, a condition of having inadequate or sparse eyelashes. When used for this purpose, bimatoprost solution is applied to the base of the upper eyelashes, resulting in longer, thicker, and darker lashes over time.  

Common side effects of bimatoprost eye drops include eye redness, itching, dryness, a feeling of something being in the eye, and blurred vision. Some individuals may also experience changes in eyelash characteristics (increased length, thickness, and darkness) and darkening of the eyelid skin. In some cases, the color of the iris may also change, usually to brown, and this change can be permanent.  

It is crucial to use bimatoprost eye drops as directed by a healthcare professional. If contact lenses are worn, they should typically be removed before applying the drops and can be reinserted after 15 minutes. If other eye medications are being used, a 5 to 10-minute interval between applications is generally recommended. Regular check-ups with an eye doctor are important to monitor the effectiveness of the treatment and to check for any potential side effects.