# Blue-green colour vision acuity **URL:** \ **Category:** Factual Questions\ **Created:** [October 18, 2009, 5:20pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228 "2009-10-18T17:20:41Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [October 18, 2009, 5:20pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/1 "2009-10-18T17:20:41Z")
I am, for some reason, fairly bad at telling blue and green apart. I can tell that the Straight Dope colours are red, yellow and blue, and I think these smileys are :eek: blue, :rolleyes: green , šŸ˜› green, :D, grrā€¦ blue and ā˜¹ blue. But I wouldnā€™t be surprised to be told that the smileys are ā€œactuallyā€ not like that, and I scored an 88 (0 being best) on [this test](http://www.xrite.com/custom_page.aspx?PageID=77), with blue green being the worst. Is this common? Is it something to do with my cones, or my brain? And are there other colour acuity tests out there? ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [October 18, 2009, 6:25pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/2 "2009-10-18T18:25:14Z")
My dad is colorblind and has bought several purple ā€œblueā€ shirts and hats. ---
**Author:** ![Hello\_Again](https://avatars.discourse-cdn.com/v4/letter/h/85e7bf/32.png) [@Hello\_Again](https://boards.straightdope.com/u/Hello_Again)\ **Post date:** [October 18, 2009, 6:41pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/3 "2009-10-18T18:41:10Z")
There is a type of colorblindness called Blue-Yellow colorblindness, which affects the ability to distinguish green from blue. [http://www.colblindor.com/2006/05/08/tritanopia-blue-yellow-color-blindness/](http://www.colblindor.com/2006/05/08/tritanopia-blue-yellow-color-blindness/) Thereā€™s a little test for it here: > **[Tritanopia Color Vision Deficiency Test(V2)](https://www.biyee.net/color-science/color-vision-test/tritanopia_test.aspx)** > > Tritanopia (a.k.a. blue blindness) Test. This is the older Java version that is no longer supported (choose the choice that looks most similar to the bigger sample) ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [October 18, 2009, 7:20pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/4 "2009-10-18T19:20:08Z")
> [@naita](#): > > I think these smileys are :eek: blue, :rolleyes: green , šŸ˜› green, :D, grrā€¦ blue and ā˜¹ blue. For the record, the ā€œbig grinā€ is green. ---
**Author:** ![Delayed\_Reflex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/delayed_reflex/32/3172_2.png) [@Delayed\_Reflex](https://boards.straightdope.com/u/Delayed_Reflex)\ **Post date:** [October 18, 2009, 7:49pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/5 "2009-10-18T19:49:40Z")
Iā€™d call šŸ˜ƒ more of a teal myself. I remember stumbling upon this [Wikipedia article](http://en.wikipedia.org/wiki/Distinguishing_blue_from_green_in_language) on the distinction between blue and green in language - apparently not all languages distinguish between the two. Makes you wonder if there are actual differences in peopleā€™s perception, or is it more a matter of how they are expressing what they perceive. Would you describe [Teal](http://en.wikipedia.org/wiki/Teal_%28color%29) as being closer to green or blue? ---
**Author:** ![badlyburnttoast](https://avatars.discourse-cdn.com/v4/letter/b/ad7895/32.png) [@badlyburnttoast](https://boards.straightdope.com/u/badlyburnttoast)\ **Post date:** [October 18, 2009, 8:39pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/6 "2009-10-18T20:39:29Z")
I got a 4, and all 4 of my mistakes were in the blue-green area. If [Wikipedia](http://en.wikipedia.org/wiki/Color_vision) is accurate it looks like the human eye has a real low point in sensitivity around 480nm - 500nm or so between the small and medium cones, which corresponds with blue-green. No wonder many cultures donā€™t distinguish between the two and thatā€™s a trouble point on the test. FWIW Iā€™d say teal is more green then blue. ---
**Author:** ![EdwardLost](https://avatars.discourse-cdn.com/v4/letter/e/bbe5ce/32.png) [@EdwardLost](https://boards.straightdope.com/u/EdwardLost)\ **Post date:** [October 18, 2009, 8:41pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/7 "2009-10-18T20:41:26Z")
The purple=blue thing is what I have. Iā€™m pretty sure I have a decreased sensitivity to red making me ā€œred/green colorblindā€. What you have is less common. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [October 18, 2009, 9:21pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/8 "2009-10-18T21:21:01Z")
> [@naita](#): > > I am, for some reason, fairly bad at telling blue and green apart. I can tell that the Straight Dope colours are red, yellow and blue, and I think these smileys are :eek: blue, :rolleyes: green , šŸ˜› green, :D, grrā€¦ blue and ā˜¹ blue. But I wouldnā€™t be surprised to be told that the smileys are ā€œactuallyā€ not like that, and I scored an 88 (0 being best) on [this test](http://www.xrite.com/custom_page.aspx?PageID=77), with blue green being the worst. > > Is this common? Is it something to do with my cones, or my brain? And are there other colour acuity tests out there? No way I even going to attempt that test. If I did I would end up with one major headache ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [October 18, 2009, 9:23pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/9 "2009-10-18T21:23:26Z")
> [@naita](#): > > Is it something to do with my cones, or my brain? Itā€™s your cones. > [@naita](#): > > And are there other colour acuity tests out there? Lots (and most much easier and quicker to do than the one you linked to). Google ā€œcolor blindness testā€. (Although many of the online tests are just for the more common Red-Green form of colorblindness.) ---
**Author:** ![mlai](https://avatars.discourse-cdn.com/v4/letter/m/e5b9ba/32.png) [@mlai](https://boards.straightdope.com/u/mlai)\ **Post date:** [October 18, 2009, 9:45pm UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/10 "2009-10-18T21:45:18Z")
I got a 3, and likewise, all of my mistakes were also in the blue-green area. Iā€™m male, by the way. ---
**Author:** ![Magicicada](https://avatars.discourse-cdn.com/v4/letter/m/c67d28/32.png) [@Magicicada](https://boards.straightdope.com/u/Magicicada)\ **Post date:** [October 19, 2009, 1:41am UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/11 "2009-10-19T01:41:37Z")
I took the test, and I now understand some of the looks Iā€™ve gotten in the past. Also, sometimes I could only see one set of colored blobs. I assume this isnā€™t good. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [October 19, 2009, 4:33am UTC](https://boards.straightdope.com/t/blue-green-colour-vision-acuity/514228/12 "2009-10-19T04:33:31Z")
Most forms of color blindness (except for the very rare cases of people with no functional cones at all) do not cause any very significant problems. Heck, nobody even realized that colorblindness existed until 1794, when [Dalton](http://en.wikipedia.org/wiki/John_Dalton#Colour_blindness) realized he had it. Most colorblind people are unaware of it, and it really doesnā€™t matter. I assume it must have mattered to some of our primate ancestors.