Abstract: Some factors affecting the accuracy of depth discrimination anddistance judgment were studied in this experiment. The results showedthat depth discrimination and distance judgment were found to be mostaccurate normal binocular observation at 0°. Errors increased obviouslyin binocular observation at 45°sidewise, and the largest errors occurredwhen using one eye only. To compare the accuracy of relative distancejudgments, it was found that judgment of the relative distance of 2/4 wasmore accurate than that of the 1/4 and 3/4. The coordinative movementof both eyes looking through binocular are very important factorsaffecting depth discrimination and distance judgment.

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