Transl Vis Sci Technol 2019 Jan 28;8(1):25. Epub 2019 Feb 28.

Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK.

*Purpose*: To describe a new stereotest in the form of a game on an autostereoscopic tablet computer designed to be suitable for use in the eye clinic and present data on its reliability and the distribution of stereo thresholds in adults.

*Methods*: Test stimuli were four dynamic random-dot stereograms, one of which contained a disparate target. Feedback was given after each trial presentation. A Bayesian adaptive staircase adjusted target disparity. Threshold was estimated from the mean of the posterior distribution after 20 responses. Viewing distance was monitored via a forehead sticker viewed by the tablet's front camera, and screen parallax was adjusted dynamically so as to achieve the desired retinal disparity.

*Results*: The tablet must be viewed at a distance of greater than ∼35 cm to produce a good depth percept. Log thresholds were roughly normally distributed with a mean of 1.75 log arcsec = 56 arcsec and SD of 0.34 log arcsec = a factor of 2.2. The standard deviation agrees with previous studies, but ASTEROID thresholds are approximately 1.5 times higher than a similar stereotest on stereoscopic 3D TV or on Randot Preschool stereotests. Pearson correlation between successive tests in same observer was 0.80. Bland-Altman 95% limits of reliability were ±0.64 log arcsec = a factor of 4.3, corresponding to an SD of 0.32 log arcsec on individual threshold estimates. This is similar to other stereotests and close to the statistical limit for 20 responses.

*Conclusions*: ASTEROID is reliable, easy, and portable and thus well-suited for clinical stereoacuity measurements.

*Translational Relevance*: New 3D digital technology means that research-quality psychophysical measurement of stereoacuity is now feasible in the clinic.