Mathematical modeling of retinal birefringence scanning

Retinal birefringence scanning (RBS) is a new technique that is used to det ect the fixation of the eye remotely and noninvasively. The method is based on analysis of polarization changes induced by the retina. In this study, the principles of RES were mathematically modeled to facilitate a better un derstanding of the origins of the signals obtained. Stokes vector analysis and Mueller matrix multiplication were augmented with Poincare sphere repre sentation. The cornea was modeled as a Linear retarder. The foveal area was modeled as a radially symmetric birefringent medium. The model accurately predicted the frequency and phase of RES signals obtained during central an d paracentral fixation. The signal that indicates central fixation during R ES likely results from a combination of the radial birefringence of the Hen le fibers and the overlying corneal birefringence. (C) 1999 Optical Society of America [S0740-3232(99)01309-5]. OCIS codes: 070.6020, 120.5410, 170.44 60, 170.4470, 330.4300.