This book covers interpretation of visual fields by Humphrey and Octopus perimeters and discussion of Humphrey visual fields in a variety of ocular disorders.It examines dilemmas faced by an ophthalmologist while evaluating visual fields which do not match with the clinical picture. Glaucoma, the commonest condition for visual field investigation is discussed in detail. Logical reasoningfor incorporating perimetry in glaucoma management with a clear understanding of the challenges in its interpretation is delved into. The book progresses to advanced glaucoma and glaucoma progression. It discusses a systematic evaluation of various parts of the visual field so that the reader can make a calculated management plan for their patient.  Each chapter attempts to clearly enunciate factors that help in the diagnosis and features which may be confused with other conditions. Fields which help diagnosing early, advanced glaucoma and glaucoma progression with images and methodsof ensuring reasonable diagnostic accuracy are included. The book incorporates separate chapters on ocular conditions which also mimic visual field defects of glaucoma with detailed modes of correct diagnosis, diagnostic dilemmas arising from retinal, macular, vascular, visual pathway lesions mimicking visual field defects of glaucoma or while coexisting with glaucoma, supported by algorithms to achieve a quick diagnosis in a busy OPD without missing the clinical findings and by using minimal investigative modalities.   This book helps clinicians to prevent over diagnosis or under diagnosis of glaucoma and helps diagnose cases with morbidities causing visual field defects.