Talk:Fovea centralis

This page was moved from optic fovea to fovea. --M1ss1ontom a rs2k4 (T 19:25, 14 August 2006 (UTC)

Errors
Several errors here: Eg:
 * A distinction needs to be made between the clinical "fovea" and the anatomical "fovea".
 * Also, the fovea is NOT synonymous with the "foveal avascular zone"Jkokavec (talk) 10:35, 3 October 2016 (UTC)*
 * When you open ip a version of the image of the eye using the various links provided the top ½ of the image, including the text, is being blocked - almost looks like dripping paint. This is true when you try to open any size image of the eye using the provided links.*

Chromatic aberration, pigment absorption of blue light
How the presence of a blue light-absorbing pigment acts to reduce chromatic aberration is rather unlcear. A short explanation detailing how it occurs would be much appreciated! 130.113.67.105 (talk) 21:02, 31 March 2008 (UTC)

Question:

When it says: "where only cone photoreceptors are present and there are virtually no rods."

It doesn't make sense. First it says there are "only" cones, but then it says "virtually" no rods. Can someone make this more clear? I would like to know the correct answer. Thanks. —Preceding unsigned comment added by 174.7.29.171 (talk) 03:51, 6 April 2009 (UTC)

"micrometres" is a length not an area
The Quote is.."The perifovea contains an even more diminished density of cones, having 12 per 100 micrometres versus 50 per 100 micrometres in the most central fovea" —Preceding unsigned comment added by Dave3457 (talk • contribs) 19:21, 4 October 2009 (UTC)

Maybe square microns?

Nuvitauy07 (talk) 14:33, 28 October 2010 (UTC)

Rods or Cones in Parafovea
Britannica stated that the parafovea had the highest density of rods, while Wikipedia stated that it has higher density of cones. Which one is correct? Nuvitauy07 (talk) 14:39, 28 October 2010 (UTC)

Visual field
"The fovea sees only the central two degrees of the visual field, which is roughly equivalent to twice the width of your thumbnail at arm's length.[7]" First, two degrees probably is two degrees in visual angle. Second, this citation is outdated, the new edition of the book is from 2005. Third, this citation is worthless, since no research has been performed. The citation is to a book that just states exactly the same, without any citations. There is no research to base this statement on, not in wikipedia and not in the cited book. —Preceding unsigned comment added by 193.157.230.98 (talk) 13:22, 1 November 2010 (UTC)
 * The human fovea is around 5 degrees according to Franco et al. (2000) Conservation of absolute foveal area in New World monkeys. A constraint on eye size and conformation. Offspinner (talk) 02:17, 22 March 2012 (UTC)

50% of visual cortex
"The fovea comprises less than 1% of retinal size but takes up over 50% of the visual cortex in the brain." This is almost certainly incorrect. I don't know where to find the exact number, but for V1/V2/V3 it's around 30%, if you consider the human fovea to be 5 degrees. See Schira et al., (2007) "Two-dimensional mapping of the central and parafoveal visual field to human visual cortex" and Schira et al., (2009) "The foveal confluence in human visual cortex." Offspinner (talk) 02:17, 22 March 2012 (UTC)

Citation for mammalian colour vision
The current article states: "Since cones contain the pigmented opsins that allow humans to discriminate color, the fovea is largely responsible for the color vision in humans, which is superior to that of most other mammals.[citation needed]"

How about this reference to a paper written in 1993:

http://www.ncbi.nlm.nih.gov/pubmed/8347768 Biol Rev Camb Philos Soc. 1993 Aug;68(3):413-71. "The distribution and nature of colour vision among the mammals." I think that the point is that the issue is no longer considered contentious enough to write papers about it. DJMcC (talk) 13:22, 26 September 2012 (UTC)

Optical implications of the depression
The depression is further away from the lens than the surrounding retina, so if the image is in focus on the fovea it is slightly out of focus on the surrounding retina. Is this useful? Slight defocussing in an XY grid CCD reduces moire patterns, so it could stop fine detail falling between the rods. Has this been investigated? BioImages2000 (talk) 13:22, 15 January 2021 (UTC)