Randot Preschool stereo thresholds by age-group, for children with normal vision who were judged as being able to understand and cooperate with the test.

Mean and SDs are reported for those children who could complete at least the 800 arcsec test level. Percentiles (type 1 quantile from Hyndman and Fan (1996)) are for all children, including those who scored “nil”. Stereothresholds in the normal range for each age group are marked in green (up to the 75% percentile). “Nil” means unable to perform 800 arcsec plate of Randot Preschool despite passing non-stereo pre-test.