Talk:Human eye/Archive 1

Apparent Problem: Significant Discrepancy
This is NOT my field, but: What is the correct name for the space in the center of the eye? The label of the diagram (item 1) and the text under "Components" seem to describe the central, largest cavity as the "Posterior Chamber", but the separate Posterior_Chamber article specifically says the P C is a small [annular] space adjacent to the rim of the lens and implies that the larger central space is the "vitreous chamber", which the P C is not. My guess is the latter is correct and the main article is in error, but which is it, really?

BTW, this quest for knowledge was in aid of my prior intention (as a confused reader/editor) to clarify the Rod_cell article, where it says the outer segment is "pointed toward the back of the eye". What exactly does the "back of the eye" mean when you're talking about a component of the retina? The closely adjacent proximal hemisphere of the inner surface I suppose, but I didn't find that point to be made very clear in the context. I think it might be more informative (and accurate) to say the rods point "into the ??? chamber" or something along those lines.

PROJECT: Anyway, being stymied by lack of knowledge, I leave the suggestion of improvement of the Rod article also to whoever deals with the chamber labeling difficulty. Mrnatural (talk) 23:51, 19 June 2011 (UTC)

200 degree viewing angle?
Has anyone sorted this out yet? It appears not from the page. The statement "With eyeball rotation of about 90° (head rotation excluded, peripheral vision included), horizontal field of view is as high as 270°." defies all common sense as it would mean that people could see behind them without even moving their head. I certainly can't do that and I figure that the real number is actually less than 180 degrees. Next chance I get I will talk to a real optometrist and get some real answers. Tedmarynicz (talk) 14:58, 27 April 2013 (UTC)

This must be wrong. The maximum numeric value is 180 degrees. That number (200 degrees) seems to be either an eye that moves or both eyes combined, one eye in a fixed position isn't going to manage 200 degree. Could somebody who knows the true numbers clear that up? -- Grumbel (talk) 17:45, 5 March 2009 (UTC)

This Q&A may have part of the answer


 * This what I found: "Many sample photos you find in our Web site are cropped to a fixed aspect ratio of 2:1. The idea of cropping the photos at this fixed aspect ratio is based on the fact that the human's eye viewing angle is about 160 degrees wide by 75 degrees tall (which is closely resembled 2:1 aspect ratio.)" hugozam  11 March 2009

I concur: author confused two eyes for one. It would also be notable that the human nose blocks much of the FOV of a single human eye. I plan to delete the 200 degrees if nobody finds a citation.Esoteric Rogue (talk) 22:23, 5 July 2009 (UTC)
 * I copied the citation for 10 million colors from Color.
 * I found Field of View info at http://www.optiboard.com/forums/showthread.php?t=27940, post number two as follows:
 * 95o Out, 75o Down, 60o In, 60o Up,about 12-15o temporal and 1.5o below the horizontal is the optic nerve or blind spot which is roughly 7.5o in height and 5.5o in width. (these figures use a 3mm white target on a perimeter of 330o if the target was increased the temporal can be pushed to about 110o) The Ophthalmic Assistant - Stein, Slatt, Stein pg.395

However, I cannot verify the source.Esoteric Rogue (talk) 23:24, 5 July 2009 (UTC)

The angles in this section are clearly wrong and are inconsistant with the information in the citation given. Other sources (ref) list the total viewing angle (both eyes working together) as 20-30° vertical and 40-60° horizontal, which seems more plausible. This section should be deleted until the correct information can be posted. —Preceding unsigned comment added by 130.76.64.17 (talk) 17:59, 10 August 2010 (UTC)

My field of view since it seems to be somewhere between 230 and 260 degrees. And yes, I CAN see somewhat behind me without moving my head...for example, if permitted to move my eyes (as is duly though perhaps ambiguously described by the "with eyeball rotation of about 90°" statement the OP seems to take issue with), I can currently see the wall that is 2.5 feet behind me when my head is pointed perpendicularly away from it. I'm guessing I can start to see it after it is 4 feet from my position...I could do the measurements and the trig but seems pointless as it would lack authority. In any case, that would be completely impossible with a 180-degree view or less. This is perhaps explained by anatomical differences where the eyes are not sunken as deeply on some people. My own view is finally obstructed by my face, not by the curvature of my eyeball or ability to turn my eyes. Also, I do not have a particularly unusual facial structure. However, if NOT permitted to move my eyes, my FOV seems to be a hair over 180 degrees, perhaps 185-190. So it seems the main source of confusion is whether FOV is defined by "what is observable at any given moment" and "what is observable when the eye is rotated to its maximum."

But we shouldn't guess at numbers without any authoritative sources that shows averages and standard deviations. It clearly varies - markedly so, if the UK is testing if people's FOVs are below 120 degrees. (Source for UK testing is http://en.wikipedia.org/wiki/Visual_field#Normal_limits, which also suggests an uncited 200-degree normal range.)

Diagrams: http://www.vision-and-eye-health.com/images/VisualFieldHoriz.gif

http://www.technologyreview.com/sites/default/files/legacy/2-visual-acuity.jpg

96.39.225.181 (talk) 22:50, 20 May 2013 (UTC)

Cuisine
Shouldn't the 'Cuisine' section be in the more generic 'eye' article, or perhaps 'mammalian eye'? It's not like human eyes are mentioned in it. (unsigned comment by 68.39.72.221, 00:52, 12 September 2008)

Intro
"The human eye is the eye of a human" - What the hell. I am not much of a writer, but gah.   Ase ' nine ' '' 22:19, 29 September 2008 (UTC)


 * Haha, is "The human eye is similar to most mammalian eyes" any better? I think this is the first time I've laughed out loud at Wikipedia, when I saw "This article's introduction section may not adequately summarize its contents" next to that.
 * Understatement of the year :D
 * Sparrer (talk) 23:06, 7 January 2009 (UTC)

an impressive 72 GB of data (per second)
Uhmm... Someone might want to check their math. If that number is correct, then I can arrange over a hundred high definition televisions before me and have every pixel of every frame of every television reach my brain. Maybe I simply have vision problems, but my eyes can't do that working together, let alone just one by itself.

This remindes me of something I read on Slashdot once. Someone decided to estimate the bandwidth of the optic nerve. Their reasoning went that they can see individual pixels on their monitor which is running 1024x768, they can notice a 60 Hz refresh rate, and they can notice aliasing in color gradients even with 24-bit color, and so they estimated that the optic nerve has at least 142 MB/s of bandwidth.

Apparently this person never noticed that, while they might be able to see pixels in the middle of their monitor, they can't look at the center of their monitor and simultaneously recognize even large icons at the corners of the screen, let alone also see the pixels at the corner of the screen. There's also a difference between noticing a refresh rate and actually seeing what is on every individual frame, for example, a video camera recording one frame per second can notice a 60 Hz refresh if it's exposure time is 1/100 of a second. ...and as I've read somewhere once, the eye doesn't so much tell the brain an absolute color value as it tells it the difference between adjecent rods or cones, so while you can see the difference between similar 24-bit colors when placed side-by-side, seeing the difference between them when they aren't side-by-side is an entirely different matter since the rods or cones can't directly compare and so the brain has to compare the two by summing the difference of all of the rods or cones in between. ...or so I think I know.

I've read in unknown places that the eye has about 40,000 "pixels," 15 frames/second is apparently all that is necessary for the brain to see animation, and 12-bit color is probably pushing the limit of what people can perceive, so let's say 1 MB/s. Well, that is, if we must play this game of "let's compare man to his creations" or whatever it's called. Sure, I just made that number up out of figures I only kind of think I remember, but I suspect it's more accurate than 72 GB/s, regardless of what metric one has to invent in order to compare the accuracy of such gibberish. -- The one and only Pj (talk) 02:22, 12 November 2008 (UTC)

A doctor once told me the eye can send up to 100 frames per second, but smooth animation is achieved at 24 Hz (hence the 24 fps television)... Not sure about the first part though. Also, you dont know how the human eye sends its information to the brain so you also dont know how much "Mb/s" that would be, how do you even know the human brain uses bytes?86.86.36.63 (talk) 20:08, 22 April 2009 (UTC)

Development?
What I want to know is... what are the developmental characteristics of the human eye? For instance, do our eyes grow in size as we mature? It seems to me that we're born with eyes of a particular size, and they stay that size into adulthood... but I could be wrong. Fuzzform (talk) 03:46, 30 January 2009 (UTC)
 * See Eye, Talk page, section: 'Growth of eyes'. - Hordaland (talk) 04:22, 30 January 2009 (UTC)

Needs some clean-up.
Some parts of this article are a disaster:


 * Eye transplants can happen but the person receiving the transplant will not be able to see.


 * 1) They "can happen"... by accident, spontaneously?
 * 2) If an eye transplant cannot achieve its primary and only objective, restoring vision, then what is the definition of "can happen"?

I'll see if I can fix a few bits, but this really needs some heavy work (and source citations of course)...

--- Arancaytar - avá artanhé (reply) 14:46, 6 February 2009 (UTC)


 * It seems that at some point in the past someone tried to "improve" this article by sprinkling it with middle-school textbook wow-speak ("The human eye is very complex. It has the amazing ability to transmit important information to the brain by sight!") as well as out-of-context trivia (two sentences about ocular nerve damage in the paragraph about eye movement). I've removed some of these now. --- Arancaytar - avá artanhé (reply) 15:00, 6 February 2009 (UTC)


 * Agreed. I toned it down some more.  - Hordaland (talk) 17:14, 6 February 2009 (UTC)
 * Thanks. I hate reading redundant sentences.86.86.36.63 (talk) 20:10, 22 April 2009 (UTC)

"Some" clean-up???
'''THIS WHOLE ARTICLE IS A MESS, A COMPLETE DISASTER. IT WOULD GET A "D" IN ANY DECENT MEDICAL SCHOOL. TO TRY TO MEND IT IS HOPELESS, A WASTE OF TIME. HENCE, IT SHOULD BE DUMPED AND REWRITTEN FROM SCRATCH --BY EXPERTS IN THE FIELD, NOT BY MERE AFICIONADOS! ''' --SciCorrector (talk) 22:24, 1 December 2009 (UTC)

The only person qualified to give constructive criticism is someone willing and able to undertake construction. —Preceding unsigned comment added by 209.134.45.218 (talk) 06:05, 28 December 2009 (UTC)


 * FWIW, I don't agree with either of you. :)  - Hordaland (talk) 12:52, 28 December 2009 (UTC)

Eye irritation
Um, I don't know what a section "Eye irritation" is doing within the section "Dynamic range". Aside from that, shouldn't the bulk of the info about eye irritation perhaps be moved to Eye disease or somewhere? - Hordaland (talk) 02:36, 2 May 2009 (UTC)
 * It's now so thorough that it's worth its own article, with just a Main:summary here. - Hordaland (talk) 09:57, 25 August 2009 (UTC)

suggest adding a link to a site which helps people by notifying them to rest their eyes every 30 minutes from the computer monitor. http://www.restyoureyes.info/ —Preceding unsigned comment added by 58.173.133.244 (talk) 10:28, 1 August 2010 (UTC)

Rods and cones
No mention of rods or cones? This article could benefit from copying some material from the newly expanded Optics article. When copying material from one Wikipedia article to another, remember to state in the edit summary where it came from and give a link to the original page, to give attribution under GFDL to the Wikipedian authors (see WP:SPLITTING). ☺ Coppertwig (talk) 15:21, 30 May 2009 (UTC)
 * The hierarchy-idea, Eye > Mammalian eye > Human eye, has gone too far, leaving some essentials to parent article(s). - Hordaland (talk) 22:36, 30 May 2009 (UTC)

Suggestion for edit
The beginning of the article states that the eye allows "conscious ... perception." This is not correct; certain pathways of the visual system in the brain allow conscious perception, and much of visual perception is not conscious. The eye allows the transduction of visual stimuli into visual information in the nervous system. This needs correction by an expert in the article. 173.52.153.51 (talk) —Preceding undated comment added 03:09, 13 July 2009 (UTC). Clarifying FoV, I believe it was meant that out is away from the nose and in is toward it.

Suggestion for additions
There is no information in the article on theories and research findings on the evolution of the human eye. As this is an article about human eyes, it should say something about the ways in which human eyes differ from other primate eyes, other mammalian eyes, and the eyes of vertebrates and invertebrates, including the evolutionary reasons for the similarities and the differences. 173.52.153.51 (talk)

Suggestion for addition
There is no section on eye resolution. I went to look for that and could not find it. I understand that the eye can resolve detail up to 100um in width but a derivation of that from typical vlaues of minimum focal distance and density of rods and cones would be very useful and make interesting reading.

No focal length discussion either. — Preceding unsigned comment added by 76.90.93.126 (talk) 00:28, 25 November 2012 (UTC)

Additional omissions of important information
Much of this article pertains to functions of the nervous system, but the nervous system is not mentioned. The reader is left with the impression that the eye somehow magically accommodates, adjusts, and moves, as if these are functions that are performed by the eye itself. In actuality, these are functions of the central nervous system, which the musculature of the eye executes. This needs to be corrected. Otherwise the article will remain hopelessly concrete. 173.52.153.51 (talk)

Eye vs. vision
It would appear that most of the article pertains to Vision, not The Eye. 173.52.153.51 (talk) —Preceding undated comment added 03:16, 13 July 2009 (UTC).
 * That's been my complaint about most or all of the eye-articles including the evolution one! For centuries, nay, millennia, we've assumed that the primary function of eyes is and always was vision.  Chronobiology only got going as a field 50 years ago, and it took a good while before researchers were on the same page (umm, to the degree that they are on the same page).  Every living thing has its circadian rhythm so that explains the original need for photosensitivity.  Vision came later.  This newer knowledge gets patched into the eye-articles, but they then look like patchwork.  - Hordaland (talk) 10:15, 25 August 2009 (UTC)

Ocular Fauna
This might sound really strange, but I've been told it's true. Sadly I couldn't find anything on it on the web and want to know if anyone knows what I am referring to. Is there any place with information on the kind of 'wildlife' that inhabits the water on our eyes?

This is what what I'm saying leads to: What is the name of that phenomenon where one looks at the sky and floating in our eyes we can see small particles moving around?(we are never aware of them until we pay attention closely to what we see). I was told they are called 'milos' and that thet are actually living things, but does anyone have some knowledge on this?

Thanks so much! —Preceding unsigned comment added by 200.120.249.211 (talk) 06:02, 30 August 2009 (UTC)


 * They are called Muscae volantes, or floaters. They're "living things" as much as the Gnomes beneath your bed. --SciCorrector (talk) 22:32, 1 December 2009 (UTC)

Quite right about floaters but there are also "moving bright points". These correspond to the retinal capillary circulation, specifically gaps between red cells.RayJohnstone (talk) 16:28, 21 November 2010 (UTC)

Size of the Fovea
Just doing research into this myself, and I don't see any references to the statement "This area is called the fovea, and covers about 2 degrees of visual angle in people".

Well, I found a reference, and a slightly different number. Curcio et al states that horizontal diameter of the rod-free zone of the fovea is 0.35mm or 1.25 degrees. That's the best hard numbers definition of the size of the fovea that I can find. JodiTheTigger (talk) 22:54, 7 October 2009 (UTC)

Picture!
This picture- shows an orb I guess, labeled in tiny Latin... from an angle few of us will ever actually see an eye. Nor does this picture gives any sense of where the orb belongs on the body of any mammal- nor does it give a sense of where actions of vision occur, on the retina. Here the retina is just another oddly-angled stripe of tissue. This image is the opposite of informative. I came to the article to check some names of parts of "the eye"- but they arent even listed anywhere here! "The Eye" is not just "the orb". I suggest any "encyclopedic" image includes "gross anatomy"- the closely-related structures-ie., tear ducts, caruncle, eyelid, lashes... And places these in some kind of recognizable relationships. However I suggest no single image will do; and I suggest that Conjunctiva has far better images which Eye here ought to also use. _  Hilar leo  Hey, L.E.O. 07:20, 23 January 2010 (UTC)

Request for addition
I undersatnd that people ae left-eyed or right-eyed meaning that they use one eye for focusing first and then adjust the other. Could you elaborate on that, plese (ASk opticians)

Genezistan (talk) 06:53, 2 September 2010 (UTC)

Bizarre intro: ganglion cells
The photosensitive ganglion cells are given prominence early in this article. But they comprise only 1% of all ganglion cells. This must be confusing for many readers. Ray Johnstone.RayJohnstone (talk) 16:09, 21 November 2010 (UTC

"See also"
T've added a reference to an article I've started on the reduced rye. RayJohnstone (talk) 15:42, 24 November 2010 (UTC)

Close up
Photos like these would be a nice addition: http://www.behance.net/paronsuren/frame/428809 —Preceding unsigned comment added by 91.110.255.2 (talk) 12:19, 3 January 2011 (UTC)

Pic of eye
On 1-3-11 I added File:Human eye - blue.JPG to replace the other photo of an eye as I thought this photo to have more EV on the grounds of resolution, quality, and color. The image is vastly superior to the one it replaces in these aspects. If a more representative photo is prefered, one should be found in lieu of the current photo of an equal quality to the one I presented. My photo should stay in place until such a photo is found. Thank you. Garretttaggs55 (talk) 15:21, 4 January 2011 (UTC)


 * Both current photos of "a human eye" should be replaced. They both show very visible dark eyeliner around the eye, which is irrelevant to the subject of the article, misleading as a visual representation, and creates a suggestion for a preference for cultures which use eye cosmetics. Anna8800 (talk) 21:14, 27 February 2011 (UTC)
 * Do so agree. Have replaced the upper one with brown eye and brown skin (like the vast majority of humanity).  The 2nd one should also be replaced with an eye without make-up.  --Hordaland (talk) 02:50, 28 February 2011 (UTC)

Wavelengths it is sensitive for
If this page is going to mention sensitivity, it should mention what it is sensitive for! The Cone cells 564–580 nm, 534–545 nm, and 420–440 nm, Rod cells not so clear, "sensitive to wavelengths of light around 498 nm (green-blue), and less sensitive to wavelengths longer than about 640 nm (red)".82.169.255.79 (talk) 20:02, 5 April 2011 (UTC)

Bloodshot eyes
Currently there is an image labeled "Bloodshot eye" in the irritated eye section, but no reference to the image is made and the word "bloodshot" is not used in the article anywhere else. Is a bloodshot eye an indication of irritation? Or can irritation cause an eye to become bloodshot? Or is the relationship more subtle? I feel this should either be clarified (by referencing the image or renaming it to something that is explained in the article) or the image removed. A random image with no clear link to the article only serves to confuse, not clarify. 83.117.64.26 (talk) 14:36, 9 April 2003 (UTC) (BTW ÌF Y0U Ærë oOTUCK3ROo RËÆDÍÑG THÏŠ ŸÒÛ GOT BÆD ŁÜCK¡)

Importance to appearance
I think this article should mention eyes' functions of decorative function.111.251.224.208 (talk) 02:23, 23 April 2011 (UTC)

contrast range discrepancy with Wikipedia article High_dynamic_range_rendering
The Wikipedia article http://en.wikipedia.org/wiki/High_dynamic_range_rendering says "At any given time, the [human] eye's static range is smaller, around 10,000:1." (which is slightly over 12 f-stops, or doublings.) This matches what I had read before when studying photography, but I can't find a source. This article, on the other hand says "The retina has a static contrast ratio of around 100:1 (about 6.5 f-stops)." — Preceding unsigned comment added by 98.248.34.17 (talk) 21:50, 20 May 2012 (UTC)