Random Dot Butterfly test has variable acuity ranges of what?

Random Dot Butterfly test has variable acuity ranges of what?

• A. 1200-2400 arc seconds
• B. 200-1500 arc seconds
• C. 700-2000 arc seconds
• D. 500-1500 arc seconds

Answer: (C)

Random Dot Butterfly testing gauges stereoacuity by presenting a depth-defined butterfly within a random-dot field, so success depends on detecting binocular disparity rather than contour or monocular cues. The acuity range refers to the disparities (in arc seconds) the test can present to measure depth perception. This test is designed to span a mid-to-coarse range of disparities, specifically from about 700 to 2000 arc seconds. That means it can detect depth differences from a relatively noticeable disparity down to a more challenging, finer depth cue, but it isn’t intended to measure very fine stereo like the smallest thresholds (which some other tests target). Among the options, 700–2000 arc seconds best matches how this test is designed to function. Other ranges either imply finer stereo than this test typically assesses or fall outside the test’s published range.

Random Dot Butterfly testing gauges stereoacuity by presenting a depth-defined butterfly within a random-dot field, so success depends on detecting binocular disparity rather than contour or monocular cues. The acuity range refers to the disparities (in arc seconds) the test can present to measure depth perception.

This test is designed to span a mid-to-coarse range of disparities, specifically from about 700 to 2000 arc seconds. That means it can detect depth differences from a relatively noticeable disparity down to a more challenging, finer depth cue, but it isn’t intended to measure very fine stereo like the smallest thresholds (which some other tests target). Among the options, 700–2000 arc seconds best matches how this test is designed to function. Other ranges either imply finer stereo than this test typically assesses or fall outside the test’s published range.