Tyler mentions a number of data which are present a better view on
the retinal distribution of cones. Due to the receptor density curves
of Oesterberg, it is very common that vision people
underestimate the number of cones beyond a peripheral angle of 10
degrees, resulting for instance in the concept that the
corneal full-field cone-ERG is mainly generated in the central area
of the retina.
In addition to the message of Christoffer Tyler, it might be useful
to know that in my article " Light distribution on the retina of a
wide-angle theoretical eye" JOSA (1983) 73. p 1544-1550, a number
of essential geometrical data about retinal area, retinal area per
solid angle can be found. E.g., the whole retinal area, related to a
peripheral visual angle of 100 degrees, measures 1200 to 1400 sq mm,
depending on the model of the eye ball.
Best wishes,
Aart Kooijman
> Date: Tue, 28 Oct 97 01:38:19 PST
> From: cvnet@skivs.ski.org (CVNet)
> To: CVNetList@skivs.ski.org
> Subject: CVNet - query on cone distribution
> To: cvnet@skivs.ski.org (CVNet)
> From: cwt@skivs.ski.org (Christopher Tyler)
> Subject: Cone numbers (please post on cvnet)
>
>
> The diameter of the human eye is about 25 mm (one inch, or the
> diameter of a American quarter coin). The area of the human retina
> is about 1000 sq mm.
> ..
> The foveola (avascular center of the foveal pit, containing the cones
> with the longest outer segments, at about 50 um) has a diameter
> of about 0.5 deg. It contains about 2500 cones.
>
> The bottom of the foveal pit has a diameter of about 1 deg (the
> roughly flat and rod-free zone, containing all the cones whose
> outer segments are elongated beyond the typical peripheral length
> of 20 um). It contains about 6000 cones.
>
> The fovea, with a diameter of about 5 deg (from Polyak), contains about
> 50 thousand cones.
> ...
> Many of these points are quantified in my paper:
> Analysis of Human Receptor Density, p 63 - 71
> in Basic and Clinical Applications of Vision Science, Ed. V
> Lakshminarayanan, Kluwer Academic Publishers: The Netherlands.
> Check with me if you would like a copy.
>
> Christopher Tyler (cwt@skivs.ski.org)
>
> Christopher W. Tyler, Ph.D.
> Associate Director
> Smith-Kettlewell Eye Research Institute
> 2232 Webster Street, San Francisco, CA 94115 USA
> Ph. 415-561-1640 Fax 415-561-1610
> Email: cwt@skivs.ski.org Home Page: http://www.ski.org/cwt.html
>
>
>
>
Dr. Aart C. Kooijman
professor of videology
===============================================
Laboratory of Experimental Ophthalmology (LEO)
Groningen Graduate School for Behavioral and Cognitive
Neurosciences (BCN)
Hanzeplein 1
P.O.Box 30 001
9700 RB Groningen
The Netherlands
tel. +31 (0)50 3612165
fax +31 (0)50 3611636
Videology covers the field of research into and rehabilitation of
impairments of the visual functions of
the sensory, oculomotor and central nervous system.