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WikiProject Medicine / Ophthalmology (Rated C-class, Mid-importance)
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WikiProject icon A member of the Guild of Copy Editors, Miniapolis, reviewed a version of this article for copy editing on February 24, 2015. However, a major copy edit was inappropriate at that time because of the issues specified below, or the other tags now found on this article. Once these issues have been addressed, and any related tags have been cleared, please tag the article once again for {{copyedit}}. The Guild welcomes all editors with a good grasp of English. Visit our project page if you are interested in joining!
Please address the following issues as well as any other cleanup tags before re-tagging this article with copyedit: Merge proposal

Color Blindness elimination[edit]

Color Blindness or Daltonism is a human condition that doesn't show symptoms of monochromacy and then it will be better to remove information about color blindness from monochromacy. See Color_blindness. Moreover many information about color vision are in Color_vision, both for humans and animals. It will be better to consider here only monochromacy not to explain again color vision. — Preceding unsigned comment added by Renata.sarno (talkcontribs) 22:56, 2 March 2016 (UTC)

Blue Cone Monochromatism[edit]

I did some few corrections. There are a lot of mistakes about Blue Cone Monochromacy in this page. A full article about Blue Cone Monochromacy is in my sandbox. May I remove colorblindness from this page ? Colorblindness is not a monochromacy. Renata.sarno (talk) 17:15, 28 February 2016 (UTC)

Daltonism ? Achromatopsia ? Blue Cone Monochromacy ? please put order don't mix everything ![edit]

Humans ? Animals ? It is not really clear what you are speaking about. 1. In humans Achromatopsia is a rare genetic disorder inherited throught 4 different genes with autosomal recessive inheritance. It is a severe eye condition. 2. In humans Blue Cone Monochromacy is a rare genetic disorder inherited throught Chromosome X. It is a severe eye condition sharing some symptoms with achromatopsia but different from achromatopsia. 3.In humans daltonism with the lack of opsin MW protein or opsin LW protein is a less rare genetic conditions affecting 5-8% of males. Daltonism is inherited with Cromosome X but it is not a severe consition. People with Daltonism don't have photophobia or nistagmus or poor visual acuity. 4. other rare form of monochromacy, related to daltonic people who loose also the S-opsin protein, could not have severe symptoms because in these form of monochromacy the fovea centralis is filled of functioning photoreceptors like in daltonism.

I really think it will be important to have single articles for Achromatopsia and for Blue Cone Monochromacy as well as a page for daltonism. All these pages can be linked from pages related to inherited retinal diseases or genetic retinal diseases or eye diseases.

the situations for animals is very different.

Renata Sarno - BCM Families — Preceding unsigned comment added by Renata.sarno (talkcontribs) 16:54, 28 April 2014 (UTC)

How's that again?[edit]

Quoting article: "The perceptual effect of any arbitrarily chosen light from the visible spectrum can be matched by any pure spectral light.".

It seems to me that "any arbitrarily chosen light from the visible spectrum" means the same thing as "any pure spectral light".

I suppose that "any arbitrarily chosen light from the visible spectrum" could be INTENDED to mean "any arbitrarily chosen combination of wavelengths of light from the visible spectrum".

Will someone rewrite this to make it clearer, please and thanks? Wanderer57 (talk) 13:23, 27 May 2012 (UTC)

Monochromat capability[edit]

I question the validity of the "100 colours" statement and ref. 7 at the end of this section. DJMcC (talk) 16:06, 11 September 2012 (UTC)

I too question it. Cones do not sense gradations of colour; they sense brightness at specific wavelengths, with each cone having a different peak sensitivity and, around that peak, having overlapping responses with the other cones. It is the comparison between different signals from each type of cone that we perceive as colour. This would mean that, for a green monochromat, as the colour being viewed approached green, it would get brighter, but not "more green". A yellow light that stimulated the green cone as much as a dimmer green light, would appear to be the same colour. A yellow light that stimulated the green cone as much as a turquoise light would also appear the same. I see no way for such a person to be able to see more than brightness, I.e. Shades of grey, with bright illumination producing a skewed distribution of greys (both white and green would appear white), and dim illumination producing a more even "black and white" image, assuming normal rod function. (talk) 05:02, 29 June 2014 (UTC)

Strange statements[edit]

I question even more in this article. If you have one type of rods plus one type of cones, why should you be completely color-blind? The rods allow you to distinguish total luminosity, and the cones would (for example) allow you to distinguish "reddish" from "not reddish". -- (talk) 15:17, 11 December 2012 (UTC)

Which means, by the way, that I don't question the 100 colors questioned above. But obviously there is a contradiction in the article. -- (talk) 15:24, 11 December 2012 (UTC)
I'd like to see a study of that. It's like what I call "campfire vision", where there's a general low light level but enough long wavelength to get the L cones involved at the same time as the rods. There ought to be a bit of a color sense in that. In more typical lighting, there's not much overlap of levels where both work. The brain circuits to compare them might therefore not have much input to develop from. Just my ideas... Dicklyon (talk) 06:56, 8 January 2014 (UTC)

The reason you would be completely colour blind is that individual cones do not distinguish colours. The reason you perceive red light as being red is not because the L cones send a "red" signal, but because when exposed to red light, the L cones send a strong signal, the M cones send a weaker signal and the S cones send almost no signal at all. In other words, it is the comparison between the various signals that creates the perception of colour. When only rods are involved, we see only greyscale images, even though they are most sensitive to green light and could be thought of as M cones that are especially sensitive at low light levels. We cannot use them to distinguish between "greenish" and "not greenish" because, like all of the retinal pigment cells including the individual cones, they only send information about brightness to the brain. It is for that reason that you should question the "100 colours idea"; a cone monochromat would be able to distinguish about 100 separate levels of brightness, but could not tell you what colour is being displayed (indeed, they would have no idea what "colour" means). A green monochromat would perceive a yellow light that stimulates the green cones at 50% capacity as being indistinguishable from a blue light that stimulates the green cones at 50% capacity. Three monochromats, one red, one green and one blue, could, however, pool information and between them work out roughly what colour a trichromat would say a particular light is, just as the visual circuits in a trichromat do. At least I try (talk) 06:02, 20 December 2015 (UTC)

Tagged for copyediting[edit]

I've tagged the article for copyediting, as there are certain phrases and ways of structuring that seem out of place in an article, as well as overcapitalisation in some places. The writing also suggests potential for copyvio, so I would recommend checking for that. — Sasuke Sarutobi (talk) 22:37, 9 December 2013 (UTC)

I did some basic style and case fixes, and fixed a few errors. I don't see obvious copyvio problems. But it could still use a lot of work. Dicklyon (talk) 06:52, 8 January 2014 (UTC)

Merge Proposal[edit]

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.
Closing merge proposal and removing tags. No consensus to merge. Ajpolino (talk) 06:45, 8 January 2017 (UTC)

Achromatopsia describes the pathological phenomenon in humans, where as monochromacy describes the condition of seeing only one color. As this article points out, that could be perfectly natural in other animals. Not withstanding that difference, most of this article is dedicated to achromatopsia, and human vision is probably the primary focus of a complete article on this topic, not the fact that seals possess no blue cones. Therefore a merger and rearranging of the subject material might be in order. Both articles also possess some readability issues, with parts of each taking the tone of a technical manual. (talk) 05:25, 8 January 2014 (UTC)

I think a better idea would be to trim Monochromacy to be more about monochromacy in general and in animals, but to direct to Achromatopsia for more details on the human abnormal monochromacy. Dicklyon (talk) 06:50, 8 January 2014 (UTC)

I think it would be necessary to have a page for Blue Cone Monochromacy, a rare human genetic retinal disease inherited on Chromosome X. Blue Cone Monochromacy is a monochromacy in humans and is different from achromatopsia. It is not easy to find information about blue cone monochromacy inside this page, so I kindly suggest to have 1. a page for Blue Cone Monochromacy 2. a page for achromatopsia. In achromatopsia the cones in the human retina lose the functionality and the day vision is completely lost. Achromatopsia is an autosomic recessive disease. People with achromatopsia have only the night vision, due to rods. In Blue Cone Monochromats part of the day vision is mantained, because blue cone are functional, so in this rare disease there is monochromacy. This page about monochromacy seems to me really not clear. Renata.sarno (talk) 20:33, 28 April 2014 (UTC)

I concur. This article should keep all information on normal monochromacy in animals. Human-disease material should be merged into Achromatopsia. This article should have approximately one paragraph basic description of the human-disease, linking to Achromatopsia. Alsee (talk) 23:00, 25 September 2014 (UTC)

There is a difference between Monocromacy and Achromatopsia and both occur in humans. Both are forms of Color blindness which does have it's own page and discusses this topic.

I also agree, this article should be short, and the relevant human disease information should be in Achromatopsia. It looks like someone attempted to do something along those lines a few months ago but was reverted. Hopefully I will have time to come back and work on doing it soon. Ljeyrich (talk) 15:04, 12 February 2015 (UTC)

Achropatopsia is a (generally) genetic desaese for humans and some other animals (some dogs, etc), with many other consequences than just not seeing colors (photophobia, reduced vusual acuity, nystagmus). Monochromacy is the normal condition for some animals. So these two different words describe two very different things, so the articles should absolutely not be merged to avoid creating confusions. I agree with the previous ideas to modify and simplify the article about moochromacy. (talk) 14:27, 30 July 2015 (UTC)

I see the page about achromatopsia. In my opinion it is really important to have a page that is dedicated to this human disease, and it will be important to have a separate page dedicated to Blue Cone Monochromatism, another human disease. I agree that Monochromacy need to be a general page dedicated to color vision of animals and humans, but the absence of color discrimination is only one of the symptoms of Blue Cone Monochromacy and Achromatopsia, both have many other severe symptoms like nystagmus and photophobia. Achromatopsia and Blue Cone Monochromatism are different disease, due to different genes, it is not possible to mix or confusing them.Renata.sarno (talk) 15:58, 29 February 2016 (UTC)

Do Not Merge This Article![edit]

This article should NOT be merged with the article on achromatopsia. It is a completely different subject.

CAUTION: Do not confuse "acromatopia" (no 's') with achromatopsia (with an 's').

Achromatopia or colour deficiency is just one of the symptoms of achromatopsia. The other classic and invariable symptoms of achromatopsia are amblyopia, hemeralopia and nystagmus. Photophobia can also be expressed if the hemeralopia is severe.

If you do not have all four classic symptoms, you do not have achromatopsia.

Monochromacy, on the other hand, only deals with colour deficiency. It is one of the three types of colour deficiency. The other two types of blue-yellow colour deficiency and red-green colour deficiency. Monochromacy exists when someone has both blue-yellow and red-green colour deficiency.

The genes that cause blue-yellow colour deficiency and red-green colour deficiency are carried on the X chromosome. Because men only have one X chromosome, they will be colour deficient if their X chromosome carries the pertinent gene(s). Women, however, have *two* X chromosomes so they must inherit the gene(s) from *both* their parents.


1. A mother can carry a gene for colour deficiency without being colour deficient herself. 2. The daughter of a mother who *is* colour deficient usually will *NOT* be colour deficient (because she would need to get the same gene from her father as from her mother). 3. The son of a mother who is colour deficient *always* will be colour deficient, because whichever X chromosome he inherits from his mother, it is going to be carrying a gene for colour deficiency. 4. The son of a mother with *achromatopsia,* on the other hand, will NOT usually inherit the syndrome from his mother, because genetic achromotopsia is not caused by genes carried on the X chromasome. 5. A person with colour deficiency usually does NOT have amblyopia or hemeralopia, and almost never has nystagmus. They might not be able to see colours but the rest of their vision will usually be normal.

The achromatopia that happens as a symptom of achromatopsia, however, has NOTHING to do with either blue-yellow or red-green colour deficiency. Unlike normal colour deficiency, achromotopsia, 1) need not be caused by genetics and, 2) when it is genetic, it's not caused by the same genes.

Rather, the colour deficiency that is one symptom of achromatopsia involves the ability of the cone cells to receive and/or process light of any kind; with the result the rod cells become saturated, which causes the hemeralopia. 2601:645:C300:16DD:6DA2:295C:2C60:D470 (talk) 11:53, 18 November 2015 (UTC)

I really agree that this page has not to be merged with achromatopsia and I strongly suggest that Wikipedia needs a page about Blue Cone Monochromatism. Both achromatopsia and Blue Cone Monochromatism are genetic human disease, due to different genes. achromatopsia is a disease different from Blue Cone Monochromatism. The last one is X-linked. In my opinion a page about monochromacy is useful only for people interested in color vision. Absence of color vision is only one of the symptoms of Blue Cone Monochromacy, a severe eye disorder, or of Achromatopsia. Please don't merge and please set up a new page for Blue Cone Monochromatism ! Renata.sarno (talk) 15:46, 29 February 2016 (UTC)

The above discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.