OFF-AXIS OPTICAL-QUALITY AND RETINAL SAMPLING IN THE HUMAN EYE

Using the double pass procedure, Navarro et al, (1993; Journal of the Optical Society of America A, 10, 201-212) measured the monochromatic modulation transfer function (MTF) of the human eye as a function of r etinal eccentricity. They chose conditions as similar as possible to t hose encountered in natural viewing. We report new measurements obtain ed with conditions chosen instead to optimize retinal image quality: w e paralyzed accommodation, used a 3 mm pupil, and corrected defocus an d oblique astigmatism at each retinal location. MTFs were estimated at the tangential focus, circle of least confusion, and sagittal focus p roduced by oblique astigmatism. Though optical blur is well-known to h ave little effect on peripheral visual acuity, it can nonetheless subs tantially reduce aliasing by receptoral and post-receptoral spatial sa mpling.