Smooth pursuit eye movements and saccadic eye movements in Japanese autistic, mentally retarded, and normal young children were simultaneously measured by an eye camera system (ECS) and an electro-oculography (EOG) system. The ECS was developed in the laboratory of the Research Institute for the Education of Exceptional Children at Tokyo Gakugei University and provides unobtrusive measurement with little set-up time. However, this method requires a large amount of time for data processing with relatively poor sensitivity. Advantages of the EOG method include high sensitivity and real time data. Both methods are appropriate for use with autistic children but selection should depend on the type of autistic child being measured. (Author/DB)