2010
Volume 10, Number 3, p.p. 85–90
A proposed increase in the retinal field-of-view may lead to spatial shifts in images
Rupak Doshi1,2,* and Philip J.R. Day3
1 Dept. of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
2 St. Edmund’s College, University of Cambridge, Mount Pleasant, Cambridge CB3 0BN, UK
3 School of Cancer and Enabling Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
Visual information determines most of our spatial behaviour. Each eye projects a 2D image of the world on the retina. Here we describe a previously known, but neglected characteristic of retinal image formation, namely that light is refracted continuously, throughout the complete process. We further use a simple physical model to demonstrate an effect of this phenomenon on the retinal image space. We show that in a monocular-like imaging system, an increase in field-of-view (FOV) is observed when water is used to model the optical fluids: the aqueous and vitreous humours. This effect was not a mere optical defocus, nor was it a result of changing the power of the lens etc., but solely due to the addition of water enabling continuous refraction. Spatial shifts in the retinal image due to the increase in FOV were convergent, and directed towards the fovea. The trend complements the photoreceptor distribution pattern, incidentally pointing to a prospective new role for ocular fluids in the image formation process. Possible implications of these shifts on the veridicality of perceived egocentric object location are discussed.
Keywords: egocentric object location, increased field-of-view (FOV), retinal image, visual optics