Glaucoma is e degenerative neuropathic disease which can be divided in to open angle glaucoma and close angle glaucoma. The main focus of this thesis is pharmacological treatment of open angle glaucoma. Antiglaucoma medications generally is divided to two categories based on mechanism of action: 1. Drugs that decrees aqueous humor production: Beta blockers, Alpha adrenergic, CAIs. 2. Drugs that improve outflow, and drainage of aqueous humor either throw TM/SC pathway or through uveoscleral pathway: Prostaglandin analogs, Cholinergic agents, RKIs. Mechanism of actions and side effect of all these drugs has been mentioned.