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|This article is written in British English, which has its own spelling conventions (colour, travelled, centre, realise, defence), and some terms used in it are different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus.|
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|Wikipedia CD Selection|
- 1 Eye Image
- 2 Placental Mammals Clarification
- 3 background:dimgray; color:#ffffff;"
- 4 "The Creationist Perspective"
- 5 New, long section on the retina
- 6 Retina essay
- 7 Visual acuity
- 8 Color or colour
- 9 Robotic eye?
- 10 Is it possible that at night is visible only specular highlights of material?
- 11 superposition, apposition
- 12 Do eyes grow?
- 13 Comment on "Eye Evolution" section in main article, http://en.wikipedia.org/wiki/Eye#Evolution
- 14 Contradiction
- 15 Pupula Duplex
- 16 Rename this article to Eye (biology), for the purpose of disambiguation
- 17 Nutrients section - wrong title and wrong placement
- 18 Some images in section "Additional images" are too vague.
- 19 Compound eye "growth"
- 20 Illustrations of eye types
- 21 File:Calliphora vomitoria Portrait.jpg to appear as POTD
- 22 The brain flips the inverted image?
- 23 "This capitulates the function of the eye."
- 24 A lens and retina in single-celled plankton
- 25 Date for eye origin
- 26 I'm not sure this is accurate
Consider comparing the two following images, and possibly replace if necessary? I'm not sure which is better for the article.. One looks faded/blurry, the other looks over-sharpened.. and . Looking for another opinion here.. Thanks! Ard0 (Talk - Contribs) 14:03, 12 June 2009 (UTC)
Placental Mammals Clarification
"With a few exceptions (snakes, placental mammals), most organisms ..." Does "placental mammals" mean placental mammals while they are in the womb or placental mammals for their whole life? 22.214.171.124 (talk) 05:44, 5 August 2009 (UTC)
- According to the Encyclopedia Brittanica, a placental mammal is "any member of the mammalian group (cohort Placentalia) characterized by the presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus. The placentals include all living mammals except marsupials and monotremes."  Woodcutterty (talk) 18:04, 12 November 2009 (UTC)
An IP just changed "background:dimgray; color:#ffffff;" to "background:dimgray; color:#000000;"
"The Creationist Perspective"
Having this paragraph as the first after the overview is a nonsensical example of WP:UNDUE: is this article about the eye, or is to be used as yet another platform to expound creationism? Although the eye provides an important example, having "The Evolutionist Perspective" so high up the page is little better. Suggest demoting both paragraphs, shortening them and using the WP:SS process to refer to the separate, well-furnished articles on these topics. And what's wrong with the title of the subsidiary article—"Evolution of the eye"— that it can't be used for the section here? "Evolutionists' perspective" introduces unnecessary controversy to what should be a factual examination of the topic. --Old Moonraker (talk) 19:55, 11 February 2010 (UTC)
- I've just compared the equivalent "creationist" information on Conservapedia's "Eye" article. It's actually better balanced, with respect to the rest of the piece, than the material here. Now how did that happen? --Old Moonraker (talk) 10:26, 12 February 2010 (UTC)
New, long section on the retina
The article is 59 kilobytes long. A new and long (about 1780 words) section on the retina has recently been added to the end of the article, all apparently from one and the same book (presently ref #40), by a new user. No reference to our article Retina. No wikilinks (until I added a couple). I have two concerns:
- Suspending Good Faith for an instant, one can wonder if this all is original writing or not. If it is original writing, it is a considerable piece of work and the new editor should not be discouraged.
- Shouldn't the information, or most of it, be moved to (merged into) the article Retina?
This addition is an essay-style piece about the retina. It's in the wrong style, it isn't referenced and it's on the wrong page. The big problem, however, is that it's a WP:COPYVIO from Physiology of Sensory Sytems, here. Suggest a revert. --Old Moonraker (talk) 06:08, 31 May 2010 (UTC)
- You are right. I couldn't find the exact formulations at Google books in the book given as ref, but the article you found does indeed appear to be the source. (It's in itself a usable source!) I'll revert. - Hordaland (talk) 06:37, 31 May 2010 (UTC)
The text "For example, if each pattern is 1.75 cm " should say "For example, if each pattern is 17.5 cm" otherwise the angle obtained is just 0,1 degree instead of 1 degree —Preceding unsigned comment added by 126.96.36.199 (talk) 14:43, 31 May 2010 (UTC)
Color or colour
- Somebody's busily changing back to colour. There's also fibres/fibers, behavior/behaviour. We really ought to pick one and stick with it. --Hordaland (talk) 23:01, 18 October 2010 (UTC)
- Honestly, should we stick to American or British? — Preceding unsigned comment added by Jiayangchang (talk • contribs) 10:14, 22 September 2011 (UTC)
- More recently, British spellings seem to have become more common. Looking at the history, excluding the first stub versions (first with molluscs, then with mollusks), early versions are inconsistent (for example, center alongside humour). However, after the first major expansion of the article by OldakQuill, British spellings (including -ise, as in maximise) prevail (). Past efforts for spelling standardization, both American→British ( ) and British→American ( ), seem to have been short-lived and have only focused on color/colour variation, leaving other spellings unaffected (for example, behavior/behaviour, center/centre, fiber/fibre, humor/humour, and mollusc/mollusk). Particularly based on this version, I have standardized the spelling to British English throughout. Some standardized rigour (talk) 07:50, 25 January 2012 (UTC)
- Honestly, should we stick to American or British? — Preceding unsigned comment added by Jiayangchang (talk • contribs) 10:14, 22 September 2011 (UTC)
Why is Robotic Eye listed as a section herein that is empty, where Mammalian eyes and other animal eyes are listed in a "See Also?" Seems to me that if the section is here with nothing in it then it shouldn't be here at all, but there should be some talk going on about it. I am gonna nuke it. —Preceding unsigned comment added by 188.8.131.52 (talk) 16:08, 29 March 2011 (UTC)
Is it possible that at night is visible only specular highlights of material?
Is it possible, that since specular lighting have white-gray color, there is not possible to recognize color in dark place? I mean, what if at night seeing objects only in gray scale is because of objects specularity of gray light? I mean, object is barely recognized only from specular light and thus don't have color. Specular light of object is more shiny wan color. And if there is at least [little bit] more light, then color [of object] is possible to recognize.
Another reason why in dark hard distinguish colours is that for example orange color have stronger red and weaker green and in dark green color is under threshold of visibility and red is visible yet, so orange looks like red in dark. — Preceding unsigned comment added by Versatranitsonlywaytofly (talk • contribs) 16:19, 4 October 2011 (UTC)
Versatranitsonlywaytofly, the real reason that we do not see colour at low light levels is that the cone cells that our eyes see colour with are much less sensitive to light than the rod cells that we see with at night. This is described elsewhere on Wikipedia. We see the specular highlights in colour if they are bright enough to excite our cone cells. DJMcC (talk) 16:15, 6 April 2012 (UTC) Another possible cause of reduced colour in specular "highlights" is that often, the reflected light spectrum is dominated by the refractive index, n, of the reflecting medium, not by the extinction coefficient, k. Usually, n is less wavelength-dependent than k. Hence less colour, even when light levels are high enough for cone vision. DJMcC (talk) 12:29, 7 April 2012 (UTC)
Do eyes grow?
Do eyes grow? well do they? — Preceding unsigned comment added by 184.108.40.206 (talk) 00:32, 1 March 2012 (UTC)
Yes, according to the NIH: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2246098/ "The mean maximum axial lengths in the neonatal and adult human eye are approximately 17 and 23.8 mm respectively. Most of the post-natal growth of the eye occurs within the first three years with posterior segment expansion accounting for over 90% of post-natal growth." Of course, it doesn't grow in proportion to the rest of the body, but it does grow. The growth of the lens along with that of the posterior chamber allows continued focussing ability. DJMcC (talk) 09:47, 2 April 2012 (UTC)
Comment on "Eye Evolution" section in main article, http://en.wikipedia.org/wiki/Eye#Evolution
"The thin overgrowth of transparent cells over the eye's aperture,..." This really needs changing, because it implies that vertebrate eyes evolved in the same way as cephalopod eyes, with a "pin-hole camera" stage, like a nautiloid. The truth may be otherwise: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3143066/ "These protochordates had ciliary photoreceptors with a ciliary opsin and a hyperpolarizing response, and were able to regenerate 11-cis retinal in darkness." Thus, they lent themselves to the evolution of scotopic eyes, as appropriate to a later group of fish being forced up from deep, dark water by geological and climatic change. This sharply distinguishes them from early cephalopods, which inhabited well-lit, surface waters, had rhabdomeric opsins, and could regenerate 11-cis retinal merely by exposure to a second photon, because plenty of photons were available. This avoided any requirement to chemically regenerate it, allowing a simpler retina than that of vertebrates, but also denying the photoreceptors the possibility of any protection against cumulative photo-oxidative damage. DJMcC (talk) 15:28, 6 April 2012 (UTC) My comment above was intended to have a title of its own, not to be a continuation of whether eyes grow. Sorry for the missing headline. — Preceding unsigned comment added by DJMcC (talk • contribs) 15:31, 6 April 2012 (UTC) DJMcC (talk) 12:38, 7 April 2012 (UTC)
The section on Eye evolution says that the monophyletic theory of eye evolution is now accepted as fact. But the article Evolution of the eye says the opposite - namely that only visual pigments have evolved onces whereas eyes in different species have evolved separately. I came here after reading Dawkins' the ancestor's tale where he uses the eye as an example of an organ that is highly likely to evolve separately through convergent evolution.·ʍaunus·snunɐw· 01:28, 17 June 2012 (UTC)
Maunus, the opsins (used as visual and non-visual pgments) evolved only once, but imaging eyes using those opsins evolved independently many times, from non-imaging eyes. Thus, imaging eyes are not monophyletic, even though opsins are. DJMcC (talk) 11:53, 23 July 2012 (UTC)
For some reason, there is a section on the mythical condition "pupula duplex" in this article. It is not very informative, presents legend as fact, and even contains an emoticon (o.O, to be specific). Thirtysilver (talk) 03:09, 19 January 2013 (UTC)
Rename this article to Eye (biology), for the purpose of disambiguation
I suggest that this article be renamed to Eye (biology), so that the page Eye will redirect to Eye (disambiguation). The word eye has many different meanings in the English language, so it's possible that other editors could mistakenly create a link to this page while believing that the link was not about eyes in the context of biology. (e. g, The [[eye]] of a hurricane is at the center of the hurricane.) Jarble (talk) 15:44, 22 March 2013 (UTC)
Nutrients section - wrong title and wrong placement
I'm primarily working on paleontology, in particular trilobites. I have a couple of observations, that I feel not up to to perform myself, so I hope someone would be able to consider what could be done.
- I was browsing the Eye article to see if there was any explanation about the Optimum Compound Eye Design Theory of Snyder, A.W. (1977). Acuity of compound eyers: physical limitations and design Journal of Comparative Physiology A 116:161-182 and Snyder, A.W., Stavenga, D.G. and Laughlin, S.B. (1977). Spatial information capacity of compound eyes Journal of Comparative Physiology A 116:183-207. Regrettably the theory is not explained or even mentioned. The relevance for me is the application of the theory on the compound eyes of the trilobites Carolinites and Pricyclopyge, two articles that I hope to create some day, and Cyclopygidae.
- It stikes me that the subsection Nutrients is not aptly named as it describes the anatomy of the vertebrate eye. It seems to me it would be better placed as part of the section on Spherical lensed eye.
- The untitled paragraph on ocelli of insects, although being single lensed, seems out of place in the section Spherical lensed eye. I guess it is much more a facetted eye reduced to one lens. I think it may be preferable to raise the para to subsection level and create an internal link in the section on Compound eyes.
Some images in section "Additional images" are too vague.
I note that the first two images in this section depict the structure of the retina as being a single neural layer. I regard this as insufficient. A reference to, eg, the diagrams in http://webvision.med.utah.edu/book/part-i-foundations/simple-anatomy-of-the-retina/ would be better, perhaps.
Compound eye "growth"
"Compound eyes, in arthropods at least, grow at their margins by the addition of new ommatidia."
Illustrations of eye types
In my opinion, the article would benefit from illustrations of how the different eye types function. The subtypes of non-compound and compound eyes (pit eyes, spherical lensed eye, apposition eyes, etc.) are not easily ditsinguishable based on the text alone, partly because there are so many subtypes. I don't have any such illustrations, unfortunately, but would like to point out that they would be highly appreciated. — Preceding unsigned comment added by Fargetv (talk • contribs) 07:20, 4 May 2015 (UTC)
File:Calliphora vomitoria Portrait.jpg to appear as POTD
Hello! This is a note to let the editors of this article know that File:Calliphora vomitoria Portrait.jpg will be appearing as picture of the day on May 31, 2015. You can view and edit the POTD blurb at Template:POTD/2015-05-31. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. Thanks! — Crisco 1492 (talk) 00:28, 12 May 2015 (UTC)
|Picture of the day|
Compound eyes on a blue bottle fly. Unlike simple eyes, which have a single concave photoreceptive surface, compound eyes consist of a number of individual lenses (called ommatidia) laid out on a convex surface; this means that they point in slightly different directions. Compound eyes provide a wide field of view and can detect fast movement, but have low resolution.
The brain flips the inverted image?
Under Compound eyes/Other, it says: "each eyelet ... produces an inverted image; those images are flipped over and combined in the brain to form one unified image".
I can't check the reference as it's behind a paywall, but this doesn't sound right. Regardless of the type of eye, there is no reason for the brain to "flip over" an inverted image. The representation of the image inside the brain is an abstract data pattern that has no need to be oriented in the same way as the outside world, if it even has an "orientation". --Heron (talk) 20:01, 31 May 2015 (UTC)
"This capitulates the function of the eye."
This use of the word "capitulate" quite odd and difficult to understand. In what sense is it even technically appropriate?
"Capitulate" means to stop resisting. That doesn't make any sense in the context of this article.
- Agreed. I looked at the ref (abstract only) and the word isn't there. If the sentence doesn't make sense to anyone, there's no reason to have it. Deleted. --Hordaland (talk) 19:59, 9 June 2015 (UTC)
A lens and retina in single-celled plankton
Date for eye origin
One part of this article says the eye evolved 540 mya, referenced to three technical research papers on genetics, another part says in the Cambrian 600 mya (even though the Cambrian started 542 mya) referenced to a book written by a psychologist. The second one should definitely go. Right now I'm trying to figure out if proper eyes date to the first bilaterians (probably not) or to the most recent common ancestors of bilaterians and cnidarians (possibly). Zyxwv99 (talk) 01:43, 13 August 2015 (UTC)
I'm not sure this is accurate
The article states that the eye has monophyletic origins among all animals but I don't think that's correct. The genes may be monophyletic but I'm pretty sure the structure we call an eye evolved independently among vertebrates and invertebrates. The article should be changed to reflect that. — Preceding unsigned comment added by 220.127.116.11 (talk) 01:29, 17 February 2016 (UTC)
- See also the three-and-a-half year old comment, by the apparently inactive user:DJMcC, in the section entitled Contradiction above. There s/he states that
- "the opsins (used as visual and non-visual pgments[SIC]) evolved only once, but imaging eyes using those opsins evolved independently many times, from non-imaging eyes. Thus, imaging eyes are not monophyletic, even though opsins are."
- That sounds reasonable to me and it definitely should be clarified in the article. I don't feel safe doing it. Someone with expertise should please take a look!
- --Hordaland (talk) 17:31, 17 February 2016 (UTC)
- I read up on this a while back. Eyes evolved more than once, but not many times. Plants, fungi and sponges have light-sensitive structures called "eyes" by the scientists who study them, but only in a very restricted sense of "eye." The simplest organism with a true eye is Warnowiaceae, a dinoflagellate (closely related to animals).
- Of the five major branches of the animal kingdom, two are eyeless (porifera=Sponge and Placozoa), two others are known to have eyes (Cnidaria and Bilateria), while one may or may not have eyes (Ctenophora=comb jellies).
- Two genes have been identified in each of two closely related species (one of them is Mnemiopsis leidyi) of comb jellies that fit the pattern for possible type II (animal) opsin genes. Eight have been eliminated as not coding for opsins. Two have been expressed in vitro as opsins with peak sensitivities around 500 nm. In vivo one opsin was expressed through the early embryonic stage. At this point, it is too soon to tell if any comb jellies have eyes.
- Which brings us to the two remaining branches of the animal kingdom known to have eyes. Cnidaria includes jellyfish, corals, and sea anemones. Bilateria is all other animas not previously mentioned except some unclassified species. Bilateria is divided into two branches: protostomes (molluscs, arthropods, and annelid worms) and deuterostomes (echinoderms, hemichordates, and chordates).
- There seems to be a general sense that eyes did not evolve more than twice in Bilateria, once in protostomes and once in deuterostomes. There is also a sense that all bilaterian eyes may have evolved from a common ancestral eye, except that's about a 50/50. It is also widely accepted that cnidarian eyes (e.g., Box jellyfish) share a common ancestry with bilaterian eyes. However, the common ancestral organ may not have been an eye. Instead, it may have been something like a Rhopalium or "ear-eye."
- The jellyfish ear-eye is coded for by a gene that looks like a mix of PAX6 (eyes) and PAX4 (ears). People born with a defect in either gene can be born both blind and deaf. The "ear" in the jellyfish is an organ of balance (statolith), but in other animals it has evolved into the middle ear (organ or hearing). In fish it also evolved into the lateral line system (senses pressure waves). Besides an rgan of balance, the rhopalium also contains a complex camera eye and some simpler eyes.
- So this part of the mystery is still unresolved for now.