Abstract
Abstract: :
Purpose: In normal subjects, the Dimension Technology, Inc (DTI) "Virtual Window TM" (Rochester NY) autostereoscopic monitor produces stereoscopic images through the use of parallax illumination, eliminating the need for special eyeglasses or headgear. We wished to evaluate the suitability of this instrument for both patch–free monocular testing as well as binocular testing of children. Methods: A DTI Model 2018XLC monitor, having 1280x1024 pixel resolution, was used to present 3 types of stimulus configurations to 12 cooperative normal adults: (A) gray to left eye, vertical grating to right eye; (B) gray to left eye, horizontal grating to right eye; and (C) horizontal grating to the left eye, vertical grating to the right eye. Stimulus configurations (A) and (B) were used to determine whether the display might be used to perform patch–free monocular grating assessment of young children. The viewing distance was not controlled, as free–space viewing is desirable when testing children. Stimulus configuration (C) was used to determine whether binocular rivalry could be observed. Digital photographs were taken of each channel for quantitative analysis. Results: All normal adults perceived the presence of the grating in the left eye when viewing stimulus configurations (A) and (B) even though only the uniform gray stimulus was being presented to that eye. This indicated that complete isolation between the eyes was not achieved. The crosstalk resulted in 18% modulation of the gray stimulus. However, all subjects did experience binocular rivalry when presented with stimulus configuration (C), as would be expected. Conclusions: The DTI monitor does not provide sufficient isolation between channels to effectively substitute for an eyepatch in monocular testing. However, the ability to reliably create the perception of rivalry suggests the instrument holds promise for measurements of binocular cooperation and ocular dominance.
Keywords: infant vision • clinical laboratory testing • visual acuity