A glaucoma is a group of eye conditions that damage the optic nerve. It is caused by abnormally high pressure in the eye due to excess fluid. There are several types of glaucoma such as open-angle glaucoma, angle-closure glaucoma, normal-tension glaucoma, pediatric glaucoma and pigmentary glaucoma. A few of the major symptoms of glaucoma are patchy blind spots, tunnel vision, severe headache, eye pain, nausea and vomiting, blurred vision, halos around lights, and eye redness. Glaucoma can be diagnosed with the help of tonometry, visual field test, pachymetry, gonioscopy, and testing for optic nerve damage with a dilated eye examination and imaging tests. It can be treated through eye drops, oral medications, as well as surgeries and therapies such as laser therapy, filtering surgery, drainage tubes and minimally invasive glaucoma surgery. This book discusses the fundamentals as well as modern approaches to glaucoma. It presents researches and studies performed by experts across the globe. This book will provide comprehensive knowledge to the readers.