![]() The first version screening set of Euvision comprises a series of nine binocularly visible Snellen E letters and two monocularly visible Snellen-Es. The orientation ofthe ‘E’ is only visible if the images are perceived binocularly through red-green anaglyph glasses (low-pass red R26 and YG09 band-pass green gelatin filters) 14 and the observer has intact stereopsis. It also includes a dynamic version of the RDS, which had an embedded, disparity-defined Snellen-E optotype (DRDSE) that is presented in random orientations (up, down, left or right). 13 Part of the system is a stereovision module, based on a random dot stereogram (RDS), which is essentially an RDS image generator with great flexibility as the parameters of the RDSs are freely adjustable (Figure 1). 12 Stereotest disadvantages such as these create the need for more versatile tools using new technologies to be developed(e.g., tablets and smartphones) to facilitate their use.Ī new concept of stereotest: Euvision A new screening system called EuvisionTab has been developed by the University of Pécs, Hungary, and comprises software that can be used on Android devices, overcoming most of the limitations of currently available stereotests. These factors have been demonstrated to affect the ratio of both the false-positive and false-negative passes. In school or kindergarten screenings, biased results can be obtained if children have an opportunity to communicate with their friends after the evaluation. Likewise, all tests have a predetermined set of stimuli displayed on a plastic or paper board which encourages motivated children to memorise expected responses. 6-9 However, most of the conventional stereopsis tests available on the market contain monocular cues for various reasons, 10,11 and so can lead to inaccurate stereoacuity values. Since a deficit of the binocular visual function is present in amblyopia, the use of stereo vision tests has been proposed as potentially useful for amblyopia screening. 5 Accordingly, there is an evident need for a reliable screening method for the condition, which also needs to be easy to perform and fast considering that it is largely needed for young children. 4 Unrecognised amblyopia can lead to various functional deficits of the visual system that become more difficult to treat with increasing age. The worldwide prevalence of amblyopia is between 1 and 5% 3 and is approximately three times higher in an unscreened population compared with a screened cohort. 1,2 In this condition, the corrected visual acuity of the suppressed eye suffers a reduction as a consequence of the associated visual cortex changes, even though no visible abnormalities are present. I was in high school reading OMNI magazine (add that to my nerd cred), and I came across this article about a man named Dan Dyckman who developed software to make your own single image random dot stereograms.Amblyopia originates from abnormal early binocular visual experience due to strabismus, anisometropia or form deprivation in young childhood and is accompanied by the loss or severe impairment of binocular depth perception. It was a very basic 3D stereogram.įast forward several years to November, 1991. I used to reach up and try to touch them, and the illusion would break as my fingers passed through them. ![]() Where the holes in the board weren’t completely aligned, some dots floated closer to me than the rest. I found that I could see the pattern clearly even though my eyes were focused on a different plane, and the dots appeared to float in space between me and the top bunk. ![]() The views from my eyes would diverge, causing double vision, until the pattern of holes overlapped again. As I lay in bed staring up at those dots, I’d let my eyes relax. ![]() The wood panels that supported the top mattress had a grid of holes like peg board. I used to sleep on the bottom bunk of a bed, and would stare up at the underside of the top bunk. But I accidentally discovered stereograms on my own as a little kid right around the same time. Stereograms were invented by a neuroscientist named Christopher Tyler in 1979. ![]()
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