Talk:Optic nerve

Medical Question
Hello Wikipeadia

I'am hoping you can answere some of our concerns After a Nerve block for my right shoulder,I have a blind spot in my right eye. The nerve block was not performed correctly and my respiratory system shut down .When I awoke in recovery I had a loss of nasal acuity in my right eye. Any help with this concern?

- maybe they have touched some nerves that are responsible for your sight. your nasal acuity corresponds the temporal part your retina, so it is suspected that there is a lesion on your visual pathway, most probably, in the ipsilateral portion. plese try to research about, visual pathway and hemianopsia.

WP:NOT "Also, bear in mind that talk pages exist for the purpose of discussing how to improve articles; they are not mere general discussion pages about the subject of the article, nor are they a helpdesk for obtaining instructions or technical assistance." Hovea 04:24, 11 September 2007 (UTC)

Images
Nice pics but...is it just me or are there far to many Grey's Anatomy images in the gallery? Some of them are hardly related to the optic nerve. 86.1.105.242 21:10, 24 January 2007 (UTC)

Main Image
I'd say the main image was a bit too graphic!!!--Mary divalerio 19:31, 7 September 2007 (UTC)


 * Yes, this is way too much for a core article on the brain. What the hell? I decreased the size of the image to be less intrusive. Consider replacing it with an illustration and moving this one to the images section. The only illustration in the 'other images' section is too artistic over practically illustrative. There's really no reason why this should have been blown up in the center of the page. --IronMaidenRocks (talk) 18:28, 9 September 2015 (UTC)

Logic in last section
"This idea was supposedly killed off by a sudden-death debate in 1977; but that debate has since been shown as faulty on both sides, so it now seems clear that Callahan was essentially correct on his main point."

Is this implying that since the debate was flawed, Callahan must have been correct? Or is there something else indicating his correctness?

208.61.112.168 (talk) 09:46, 9 February 2009 (UTC)

Late reply after the horse has bolted!! Sorry, just recently seen your comment, and meanwhile the text itself has disappeared, (tho the topic can still be pursued by googling "Callahan & Diesendorf").

Yes, of course you are quite correct. This was carelessly phrased. I meant to write "and it now seems..." (instead of "so..."). And then after "faulty on both sides" I should have gone on to say something like this:

"so we should feel free to re-examine all the basic published data for ourselves and draw our own conclusions independently. If we do that, I think we must realize that, (although he made errors over details)...". —— Tegiap

123.2.184.130 (talk) 12:25, 24 May 2009 (UTC)

What the heckles is up with the Appendix?
I can't help but feel that it's stretching the coaxial cable analogy reeeeeally too far. —Preceding unsigned comment added by 134.36.68.234 (talk) 14:02, 24 April 2009 (UTC)

I really cannot see the point or relevance of the entire appendix section. It is off in left field from the main article. --74.124.187.76 (talk) 05:04, 14 May 2009 (UTC)

Late reply to both comments; (though meanwhile there has been an Appendectomy! -- perhaps permanent):

There is-&-was a real dilemma here. What do you do when an explanation really is "off in left field" as far as one's current audience is concerned? How do you explain an idea which goes against the grain, and do so concisely enough not to lose your readers' attention. (1) Say too little, and nobody understands at all (except electrical engineers, for whom the ideas are now commonplace). (2) Say to much, and they can't see the relevance. I don't know what the proper compromise answer is, tho I try various presentations. --- Any suggestions??

[That indeed was the problem Heaviside faced when trying to explain the counter-intuitive high-performance niceties of trans-Atlantic telegraph cables back in the 1870s and 80s, and it is essentially the same problem in explaining the ignored broadband possibilities for myelinated fibres -- as a bonus on top of their acknowledged low-frequency role.]

Tegiap (talk) 07:37, 24 May 2009 (UTC)

The so-called "anomaly"
I'm sorry if my changes seemed drastic, but this article had serious problems that demanded the removal of significant blocks of content. I don't want this to turn into an edit war, and I hope that discussion here can avert that.

This whole thing about there being significantly more photoreceptors than axons in the optic nerve is easily explained by the anatomy of the eye, as I attempted to do by adding the remarks about retinal ganglion cells. It should definitely be expanded, but not with contrived analogies to fibre optics, nor with assertions that it implies substantial processing within the eye.

If people have contributions to this article, I welcome them, but only if they are encyclopaedic.

CoderGnome (talk) 15:04, 17 May 2009 (UTC)

Maybe I misunderstand you, but your "remarks about retinal ganglion cells" seem merely to describe a static arrangement (OK in its own right) but not to explain what's going on -- and such dynamics-explanations are surely the business of physiology (as opposed to anatomy). Accordingly the anomaly seems still to be there, whether we like it or not.

As for the candidate solutions which you condemn:- These were intended as plausible hypotheses for readers to consider -- not as established facts (though indeed some readers might actually prefer the challenge of hypotheses as long as they are identified as such. Isn't that what science is about?).

Of these two hypotheses, the pre-processing concept is, I believe, a well circulated text-book suggestion. It is clearly partly true at least, but where does it stop? And maybe it is reasonable given that the optic "nerve" is part of the c.n.s.? Even if we don't yet know the answer in full, isn't it still perhaps a worthy tutorial topic?

The other suggestion of infra-red coexisting with action-potentials has suffered rough justice at your hands, in two stages: (1) Firstly you removed the Appendix-Section which offered references to cumulated-though-circumstantial evidence that the idea was reasonable (tho not proven). This may have seemed irrelevant; but without it, the unfamiliar ideas were left in a vulnerable position and dependant on mere analogy (as a short-hand). So then, (2) you were free to dismiss them as "contrived analogies to fibre optics" -- whereas a close examination of the past history of these ideas tells another story.

Meanwhile recent work has been implicating not only infrared, but shorter wavelengths as well. More on that later perhaps.

Tegiap (talk) 14:06, 20 May 2009 (UTC)


 * You don't seem well versed in the anatomy of the eye and optic nerve. As I said, the signal capacity is easily explained by the fact that the optic nerve connects not to retinal ganglion cells, not directly to photoreceptors. Each ganglion cell aggregates the inputs from many receptors, ranging from a handful in the fovea to thousands in the periphery.


 * If there is material in the old appendix that is worthy of including in the article, then you're more than welcome to include it. I am particularly interested in hearing more about this research into the role of infrared radiation and other wavelengths. My understanding was that no receptors are sensitive to these wavelengths, and thus none of this information would be transmitted along the optic nerve.


 * But this above all: cite your sources, and stick to the topic of the article. This is an encyclopaedia article, not a "tutorial", and definitely not the place for speculation.


 * CoderGnome (talk) 20:28, 20 May 2009 (UTC)

Typo?? ——— I think you mean "...the fact that the optic nerve [does] connect [--] to retinal ganglion cells, [and] not directly to photoreceptors."

I suspect that we may be closer to agreement than you think; and that the trouble is that we are "talking different languages". If so, can you put your finger on where the problem lies?

Tegiap (talk) 13:01, 24 May 2009 (UTC)


 * Sorry, that was my mistake. I had one too many "not"s; your correction is what I meant.


 * The problem, to me, lies in how unscientific the content is that was added to this article by you and others. Unsourced theories about the information transmitted over the optic nerve, analogies to fibre optics, claims of controversy where none exists, that sort of thing. At the same time, a lot is known definitively about the optic nerve that is not currently in this article. Its development, for example, is quite fascinating.


 * In the end, we both want the same thing: a high-quality article. The surest way to accomplish this is by citing good sources, and by eliminating speculation. Focus first on what we *do* know about the optic nerve.


 * Cheers. CoderGnome (talk) 04:40, 26 May 2009 (UTC)

(1) Yes "development". I strongly encourage you to write that up, especially if you have privileged knowledge about it. Are you thinking of myelination by oligodendrocytes, or what?

(2) It might be helpful to work out why you thought I had naive notions about retinal connectivity, and indeed just what naive notion you thought I had! (I imagine that you saw me as requiring each photoreceptor as requiring its own dedicated fibre to the remote visual centres, and that therefore many would simply miss out due to the competition!!!). In contrast, I just took the textbook version of connectivity for granted, but worried instead about "bits-per-second", and how the apparent-bottlenecks in the system could cope with the apparent growth of traffic as the journey progressed into the converging 'narrows'. (Clearly the system does normally cope. The question is "how does-or-could it do this feat? — Perhaps by some equivalent of 'zip-coding' &/or 'changing to broadband', or what???). If you can explain that clearly, please feel free to do so.

There are other minor matters, but they can wait.

Regards, Tegiap (talk) 17:02, 26 May 2009 (UTC)

Inviting General Comment: ———— Is this apparent "Signal-Bottleneck"-within-the-network a well-known riddle??? That was my understanding: that it was a common undergraduate cliché; though by the same token that is difficult to document. Would anyone like to comment? —— e.g. with a ref. to a textbook formulation of the issue?

It would probably be best to resolve that trivial point before I say any more in this discussion. If this riddle was NOT common-knowledge, or if it CANNOT readily be taken as patently obvious, then it begins to look like an (inappropriate) original contribution, and that was certainly not how I saw it! ———— [Anyhow: Of course that was just my point-of-departure, before going on to say other things; but let's now (belatedly) get the basics sorted out before going any further].

Tegiap (talk) 13:28, 12 June 2009 (UTC)

Tegiap, after a hiatus (i.e, I forgot about this issue), I'm still of the same opinion as before and have removed the section you put in. It's simply not scientific or encyclopaedic. If you have information you can trace to verifiable sources, then feel free to add it. But please, no more of this unfounded "bottleneck" and "riddle" crap without something to back it up.

CoderGnome (talk) 05:33, 18 March 2010 (UTC)

Function of optic nerve?
Does it just send imulses from the eyes to the visual cortex, or can it do things like control lense shape or pupil width, or movements of the eye? Also curious about the speed of nerve impulses through the optic nerves, but the article defineitely needs more info about the function of the nerve.

Nerve?
Some sources contest whether the optic nerve is truly a (peripheral) nerve rather than a tract of the central nervous system. This is currently mentioned in the lead of cranial nerve but needs explanation in detail here. Cesiumfrog (talk) 06:05, 30 March 2014 (UTC)

adding stuff
I am editing this article and will be adding material to the function and clinical sections — Preceding unsigned comment added by Anatomyczar (talk • contribs) 12:46, 8 July 2015 (UTC)

A Commons file used on this page has been nominated for speedy deletion
The following Wikimedia Commons file used on this page has been nominated for speedy deletion: You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 05:06, 28 June 2019 (UTC)
 * Optic nerve parts.jpg

Bandwidth
What's the typical bandwidth and latency of the optical nerve? If it transmits information, one should be able to measure how fast and how much, right? goiken 07:38, 9 December 2023 (UTC)