Again on the Subject of “Blue Sensitive Cones”
December 17th, 2006 | No Comments »Getting back to reality…..
I have written about the ubiquitous and totally illogical statements that abound in the literature propounding the notion that blue sensitive cones exist on the retinal surface (see: http://www.ghuth.com/?p=63).
It occurs to me that the drawings of the retina made by Pirenne (M.H. Pirenne, “Vision and the Eye, The Pilot Press, 1948) supports my assertion that it is rod-rod interactions that form one of the three primary wavelengths - the short or “blue’ endpoint of the visual band. An examination of the morphology of the retina clearly shows that the smaller rod receptors are being slowly introduced at retinal angles at and beyond one degree (the foveal region). As rod density increases there is a statistical probability that two rods will be found adjacent to one another – and, in the spirit of this explanation, form a blue sensitive site (a rod-rod apposition). The density of rods then increases with retinal angle until, at 7-8 degrees, eight rods completely surround each cone in octagonal symmetry (I have written about this octagonal symmetry that is present in the visual organs of seemingly all species). The following is a portion of Figure 28 reproduced from Pirenne. The author notes that the first rod receptor appears at 0.13 mm from the foveal center. At increased retinal angles the beginnings of rod-rod appositions is seen some of which are encircled in red. I would propose that this is consistent with the many papers (previously referenced) that show (and try to explain) the paucity of “blue cones” on the retinal surface. This is totally consistent with, even to specific retinal angles, with my explanation.
GCH
12/17/06
