The major cause of blindness in children worldwide is xerophthalmia caused by vitamin A deficiency. In addition it has other adverse effects, including increased mortality and the term vitamin A deficiency disorders (VADD) has been introduced to cover the whole clinical spectrum of disease. The ocular manifestations of xerophthalmia have been classified and a set of prevalence criteria for the detection of a problem of public health magnitude has been in use for more than two decades. The global prevalence of VADD is now well documented and World Health Organisation (WHO) receives information continuously for updating its data base on the subject. The pathogenesis of the disease is still imperfectly understood, it is not at all clear precisely why certain subjects in vulnerable communities develop xerophthalmia, while the majority are spared. A schedule for treatment of the established case has been available for a long time, but at both clinic and hospital level concentrated sources of vitamin A for treatment are frequently not available. More emphasis needs to be laid on prevention and a choice of methods consisting of large dose supplementation, fortification of food, control of precipitating infections and dietary improvement. The advantages and drawbacks of each are discussed.

PIP: This article focuses on xerophthalmia, caused by vitamin A deficiency, which is the major cause of blindness among children worldwide. The term "vitamin A deficiency disorders" (VADD) has been introduced to cover the whole clinical spectrum of disease. The global prevalence of VADD is now well documented and WHO has evidence that the number of young children suffering from subclinical vitamin A deficiency is steadily increasing. Moreover, the pathogenesis of the disease is still imperfectly understood. It is not clear why certain subjects in vulnerable communities develop xerophthalmia, while the majority are spared. Oral preparations of vitamin A are well absorbed and utilized in even severely malnourished patients. A schedule of treatment is given to serve as a guide in the full treatment process. Control of VADD involves a massive dose supplementation, fortification of common foodstuffs with vitamin A, immunization, and dietary improvement. However, each of these methods has drawbacks and advantages.