Editor,—Brimonidine is a potent, highly selective α₂ adrenergic agonist used for the treatment of open angle glaucoma and ocular hypertension. It lowers intraocular pressure by decreasing aqueous humour production and increasing uveoscleral outflow.1 2 The most common ocular and periocular side effects of brimonidine include ocular hyperaemia, itching, burning, or stinging; foreign body sensation, blurred vision, allergic, toxic, or follicular conjunctivitis, and lid hyperaemia.3 The following case describes a previously unreported periocular reaction to this medication.