Screening and sampling in studies of binocular vision

Abstract

Binocular deficits are relatively common within a typical sample of observers. This has implications for research on binocular vision, as a variety of stereo deficits can affect performance. Despite this, there is no agreed standard for testing stereo capabilities in observers and many studies do not report visual abilities at all. Within the stereo literature, failure to report screening and sampling has the potential to undermine the results of otherwise strictly controlled research. We reviewed research articles on binocular vision published in three journals between 2000 and 2008 to illustrate how screening for binocular deficits and sampling of participants is approached. Our results reveal that 44% of the studies do not mention screening for stereo deficits and 91% do not report selection of participants. The percentage of participants excluded from studies that report stereo screening amounts to 3.9% and 0.7% for studies that do not report stereo screening. These low numbers contrast with the exclusion of 17.6% of participants in studies that report screening for binocular deficits as well as selection of participants. We discuss various options for stereo testing and the need for stereo-motion testing with reference to recent research on binocular perception.

Stereo vision and strabismus

“…14,15 Some of these are listed in Table 1 along with some of their properties. At its most basic, a stereotest can aim simply to determine whether a patient has any stereo vision at all, without quantifying their stereoacuity.…”

Comparison of Stereoscopic Fusional Area between People with Good and Poor Stereo Acuity

“…Many studies have reported the abnormal functions of the binocular vision due to ametropia, anisometropia, horizontal-vertical phoria, fixation disparity and age related ocular dysfunctions. [1][2][3][4][5][6][7][8][9][10] These factors affect stereo acuity and differences in stereo acuity exist acuity among the people who are not stereo-blind.…”

The development of a free stereopsis test for active shutter displays

“…Well-known tests are paper-and-pencil tests like the TNO test and the Titmus test (for a description and comparison, see [1], [2] or [3]). These tests make use of anaglyph or polarized glasses to send different images to both eyes.…”

“…These tests make use of anaglyph or polarized glasses to send different images to both eyes. While these tests were thoroughly compared on validity and reliability in several studies [4] [3] and it is shown they are of great value in clinical practice, they are expensive and require trained people. Therefore, our objectives were three-fold.…”

“…Until now, most stereopsis tests result in categorical data with 6 (TNO) or 9 (Titmus) possible outcomes [3]. By incorporating a task component in the test, which adds additional variance in test scores, an outcome variable ranging from 0 to 20 was obtained.…”