Feline glaucoma is often insidious in onset and slowly progressive with very subtle clinical signs. As a consequence, it is likely that the disease in cats is underdiagnosed. As cats typically present late in the course of disease, prognosis for long-term maintenance of vision is poor. Patient and owner compliance with frequent application of topical medications can be a limiting factor, and represents a serious clinical challenge. This review outlines the clinical features, classification, and pathophysiology of the feline glaucomas and provides current evidence on which to base the selection of appropriate treatment strategies for cats with glaucoma.