This book is a comprehensive treatment of all facets of color blindness. Defective color vision, or 'color blindness,' is a common affliction, particularly in males, where it affects eight percent of the population. There are several different types of color deficiency, each with degrees of severity, and some people have more practical color recognition than others. This book looks at the causes of congenital color deficiency and at acquired color vision defects arising from ocular and general pathology or from the excessive use of therapeutic drugs. There are clearly-written and well-illustrated chapters on a wide variety of topics in the field. There is a section on testing, in which the design of clinical color vision tests is fully explained and all the available tests documented. Detailed information is also given on the optimum use of screening, classification, and occupational tests. Examples of typical results in different types of deficiency are included, together with advice on the examination of children and disadvantaged groups. A checklist is provided of occupations requiring normal color vision or in which color deficiency is a handicap. This is a practical book, designed for students and all professionals engaged in color vision screening, but pitched at a level that will also appeal to the non-specialist reader.