Although optic neuritis occurs relatively infrequently in childhood, it may be a complication of measles,23mumps,34chicken pox,8or pertussis;12isolated instances have been reported following a wide variety of infectious diseases including those due to protozoa.10It may also follow immunization procedures.3,16Hereditary forms may result in severe visual impairment dating from birth or may cause visual failure at almost any age.13,18,25While the majority of these are not associated with involvement of other parts of the nervous system, some may be one manifestation of a familial or hereditary degenerative disease of the nervous system.31Malnutrition of a severe degree has been found to be associated with visual failure and partial optic atrophy in children in the British West Indies,2but to date no cases have been seen in this country. Certain toxic agents and a number of drugs listed