Large Disparity Processing
The role of large disparity processing in the development of typical and atypical stereopsis
The conventional view of 3D depth perception is that information from the two eyes is fused to produce the experience of a single scene. In doing so the brain also provides extremely detailed information about the relative depths of objects. This 'fine' 3D perception has been well-documented, and is assessed by existing clinical tests of visual ability. However, 3D perception is also obtained when viewing images with very large depths that cannot be fused into a single scene. The existence of 'coarse' 3D perception has only recently been studied systematically, and its role in vision is still not well understood.
We have hypothesized that coarse 3D perception appears early in life and helps the two eyes to move together so that fine 3D perception may develop. If this is the case, then lazy eye (amblyopia), a disorder that interferes with normal visual development, may have different effects on coarse and fine depth perception. We know that children with amblyopia often have no fine 3D perception, even after treatment. Our recent experiments (published in JOV, 2013) show that perception for large depths matures early in children with normal vision, and can be normal in children with amblyopia (Vision Research, 2013). Should we be able to isolate fine and coarse disparity mechanisms we may be able to improve training protocols for individuals with disrupted binocular vision.
Dr. Deborah Giaschi, Department of Ophthalmology and Visual Sciences, University of British Columbia
Dr. Laurie WIlcox, Psychology