Glaucoma is the symptomatic condition due to the change of IOT (normal range 15 to 20 mm of Hg). Acquious is formed from the ciliary process. Glaucoma is classified as congenital and acquired. Acquired is classified as primary and secondary. Primary is further subclassified as angle closure or congestive and open angle or noncongestive glaucoma. Congestive glaucoma: is due to the non or malformation of angle of anterior chamber. Upto the 3 years known as Infantile and above as Juvenile glaucoma. It is bilateral common in male. Eyes are proposed. Cornea is hazy due to the folding of endothelial layer (Haab’s striae) AC. Deep with raised IOT. Trabeculotomy with the trabeculectomy is the operation of choice. Congestive glaucoma: It is divided into 5 stages: (i) prodromal, (ii) constant instability, (iii) acute congestive glaucoma, (iv) chronic congestive glaucoma and (v) absolute glaucoma. Signs/symptoms of all stages of congestive glaucoma with the pre disposing factors are discussed and compared with noncongestive glaucoma. Noncongestive glaucoma: There are 3 cordial signs to diagnosis (i) IOT, (ii) Field changes, (iii) Fundus changes as notching of the disc margin, change of cup: disc ratio, glaucomatous cupping, etc. All stages of primary glaucoma are treated medically and surgically. This chapter include 12 labeled diagrams and 3 charts. Secondary glaucoma: The cause of raised IOP is known as inflammatory, traumatic intra ocular tumors , Lens as phacomorphic, phacolytic, phacoanophylactic phacotoxic and due to the dislocation/sublaxation of the lens, etc. are included with its clinical features and management. Drugs induced glaucoma along with malignant glaucoma are included in this chapter.