Brimonidine tartrate ophthalmic solution is a prescription eye drop primarily used to lower elevated intraocular pressure in patients with open‑angle glaucoma or ocular hypertension. It belongs to the class of alpha‑2 adrenergic agonists, which work by reducing aqueous humor production and increasing uveoscleral outflow, thereby helping to protect the optic nerve from damage caused by high pressure inside the eye.