Microphthalmia ('small eye') and anophthalmia ('no eye') are rare congenital defects of eye development. Previous studies utilizing a variety of methodologies have estimated their combined incidence at anywhere from 4 to 30 cases per 100,000 live births. In Chuuk, Federated States of Micronesia, there have been 42 cases detected since 1988, yielding an estimated incidence of 140 cases per 100,000. A number of putative genetic and environmental causes have previously been associated with microphthalmia and anophthalmia, including vitamin A deficiency. To date, it is unclear which of these factors may play a role in the alarmingly high rates observed in Chuuk. The Chuuk Division of Public Health has proposed a study to explore these potential causes, which will hopefully shed light on the prevention of these rare but debilitating conditions.