Development of stereoscopic acuity: longitudinal study using a computer-based random-dot stereo test.

Abstract

PURPOSE: To investigate the development of stereoscopic acuity (stereoacuity) in children longitudinally. METHODS: Seven full-term normal infants whose age at the beginning of the study was between 12 and 23 weeks were studied. A computer-based random-dot test of stereoscopic vision (TV-Random Dot Stereo Test) was used to measure stereoacuity. The test was repeated at 2- to 3-month intervals until the children reached 2 years of age, and then every 6 to 12 months until they reached 5 years of age. RESULTS: All of the infants were found to have a stereoacuity of 2480 seconds of arc (2480'') with this test by 26 weeks of age. The first reliable measurement of stereoacuity was obtained from a 16-week-old infant. Stereoacuity did not improve significantly between 6 and 12 months, but it improved rapidly after 12 months. All children had a stereoacuity of 100'' with the Titmus Stereo Tests at 5 years of age, but the best stereoacuity with the TV-Random Dot Stereo Test was 229'' at 28.9 months. CONCLUSIONS: The development of stereoacuity studied longitudinally was similar to that obtained by cross-sectional studies. The TV-Random Dot Stereo Test is a useful program for measuring stereopsis in preverbal children.