Off-axis image quality in the human eye

Positional uncertainty in peripheral and amblyopic vision

“…the number of degrees of visual space/mm of cortex) rises precipitously with eccentricity (Daniel and Whitteridge, 1961;Dow et al, 1981;Tootell et al, 1982;Van Essen et al, 1984;Perry and Cowey, 1985). While these profound alterations in the anatomy and physiology of the visual pathways occur within the central IO", the optics of the eye remain approximately constant (Jennings and Charman, 1981). Thus, sparse spatial sampling in the periphery may lead to increased positional uncertainty (Snyder, 1982).…”

Spectral analysis of spatial sampling by photoreceptors: Topological disorder prevents aliasing

“…In this tiny region then there is a good fit between the nominal Nyquist frequency of the receptor array and the bandwidth of the images that can be formed on that array in normal vision. Outside the foveola, however, cone density falls off precipitously while retinal image quality remains roughly constant for some 25 deg (Jennings and Charman, 1981). For example at 6 deg eccentricity the mean inter-cone distance has increased to (30)-i deg, implying a Nyquist frequency of 15 c/deg, whereas the optical transfer function cutoff is still 60c/deg.…”

Measuring gaze of children with autism spectrum disorders in naturalistic interactions

“…Our findings in terms of exploration of the lateral field of view are consistent with this idea. Indeed, visual acuity diminishes gradually when directing the eyes sideways [15]. A strategy of eccentric viewing would therefore allow to reduce the sensory overload.…”