SOME children and rare adults possess a remarkable ability to recall visual images in great detail1. These eidetic images, unlike visual after-images, remain still while the eyes move and can be recalled long after after-images fade2. Recently, attempts have been made to confirm their authenticity in studies wherein a subject is asked to recall an eidetic image of a specified picture, superimpose it onto a new second picture, and report detail produced by the superposition of the two images2. Stromeyer and Psotka3 have utilized a similar superimposition principle using Julesz4 random dot stereograms.