Talk:Cephalopod eye

The diagram
The current diagram on this page is poor. It distorts the shape of both eyes and plays down the differences between their internal structures. I much prefer this: http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2003/Muller/structure%20of%20the%20cephalopod%20eye.htm However, the page is coyrighted, so I haven't simply pasted it in. DJMcC (talk) 10:04, 27 July 2012 (UTC)
 * Both images appear to contradict the narrative. The narrative states that cephalopods have no cornea, yet both images show a squid cornea. — Preceding unsigned comment added by 12.15.255.222 (talk) 19:45, 20 September 2012 (UTC)

The diagram, part 2
I also found that the diagram is not correct. In the octopus part, the number 1 is signalling the nerve fibers and the number 2 is signalling the retina. In the text under the image indicates that the number 1 is signalling the retina and the number 2 the nerve fibers.


 * Now it seems allright: 1 ist the retina and 2 the fibers in the octopus part, in the vertebrate part and in the text. 
 * By the way, I would think some data about presence / absence of color-sensitive sensory cells is pertinent to the topic. Who says "eye" means strictly "macroscopic anatomical structure of the eye"? 194.174.76.21 (talk) 12:49, 23 February 2018 (UTC) Marco Pagliero Berlin

A Few Suggestions
- Oberlin.24 (talk) 03:23, 1 October 2014 (UTC)
 * 1) While the article discusses how the cephalopod eye vs. the vertebrate eye forms, it doesn’t discuss why this is a comparable analysis – information should be added that this is a comparison due to their similarity of adapting to have the camera-eye trait which would be the example of their convergent evolution.
 * 2) There is almost absolutely zero information on the morphology of the eye of the cephalopod. In conjunction with this problem, the diagram showing the internal structure of the eye and the dialogue which accompanies it is only informative on the vertebrate eye and includes no true information about the octopus eye next to it. The diagram should be corrected and should include more information about the cephalopod eye, or be replaced with a better diagram and description. There should be more information included concerning the morphology of the eye in the article itself, such as what parts are included in a cephalopod eye and what are not. An example of this would be that several cephalopods, including octopuses, lack a cornea.
 * 3) As the cephalopod eye is a common example of convergent evolution there should be more information added about how it is representative of a convergent evolution on the page, including a link back to the convergent evolution page. More examples of vertebrates which show convergent evolution could also be added to enhance the article such as a convergent evolution of cephalopod and trout or other fish eyes, as well as information on the convergent evolution of cephalopod and human eyes.

Misleading depiction of optic nerve size
Per figure 3 of Wild 2014, the cephalopod optic nerve is not as compact as what was depicted in File:Evolution eye.svg. File:Evolution_eye.svg and File:Evolution eye.png merely flipped the orientation of the photoreceptors for cephalopods. There should be a note on the diagram is for illustration purpose only and not reflects reality. Since User:Caerbannog has not been active lately, we might not be able to get a updated figure from them. Mys_721tx (talk) 18:58, 4 June 2024 (UTC)


 * As the author of the SVG file I now think it should be removed or replaced. I knew practically nothing about the topic back then (and I still don't). I just traced over the PNG file as best I could. --Caerbannog (talk) 14:22, 6 June 2024 (UTC)
 * I will check around the literature to see if there are any existing freely-licensed figures to replace it. Mys_721tx (talk) 06:39, 8 June 2024 (UTC)