A study was made of the effect of changes in accommodation and convergence upon the apparent distance of an object. The binocular instrument devised made possible the variation of these ocular adjustments while holding constant all visual indicators of changing distance, such as the size and brightness of the test target. Means were provided for the measurement of apparent distance of the target as affected by the amt. of accommodation and convergence in operation. The fixation distances investigated were 50, 33.3 and 25 cm. The mean apparent distances of the target corresponding to the ocular adjustments for these 3 distances were, respectively, 41.4, 37.8 and 34.3 cm. The differences are statistically reliable. 30 subjects were used. By a 2d method of observation changes in the apparent distance of the target were reported as affected by a change of one diopter in accommodation and convergence. A fixed spatial point of reference was provided as basis for these judgments of change. 80% of the reports coincided with the ocular adjustments when both accommodation and convergence were changed together; 76% coincided when accommodation alone was changed; 73% when convergence alone was changed.