Comments on: Truelight Color Vision Test http://www.colblindor.com/2009/08/07/truelight-color-vision-test/ Color Blindness viewed through Colorblind Eyes Mon, 02 Jan 2012 18:38:03 +0000 hourly 1 http://wordpress.org/?v=3.0.3 By: Richard Kirk http://www.colblindor.com/2009/08/07/truelight-color-vision-test/comment-page-1/#comment-73940 Richard Kirk Tue, 06 Apr 2010 08:18:04 +0000 http://www.colblindor.com/?p=946#comment-73940 The colours in the diagram are not supposed to look red, green, and blue. They should look pink, an aqua colour a bit like the towel, and violet. I could have used the complimentary colour. This way around, they look vaguely reddish, greenish, and blueish, which is the colour of the corresponding colour channel in the eye that they are testing. Newton's 'blew' colour probably corresponded to modern cyan, which is why he needed 'indigo' for what we normally call blue. Thomas Young provided accurate wavelengths for the named colours, and is using the modern 'blue' in 1813, but some of his earlier papers of 1801-3 suggest he recognized and had used the older Newtonian 'blue' as well. There are several genetic variations which may shift the green receptor peak by up to 4 nm. The blue peak is pretty much the same for all of us. I don't think genetic variations are significant here. Different people seem to use different words for colours on the blue-green boundary. The colours in the diagram are not supposed to look red, green, and blue. They should look pink, an aqua colour a bit like the towel, and violet. I could have used the complimentary colour. This way around, they look vaguely reddish, greenish, and blueish, which is the colour of the corresponding colour channel in the eye that they are testing.

Newton’s ‘blew’ colour probably corresponded to modern cyan, which is why he needed ‘indigo’ for what we normally call blue. Thomas Young provided accurate wavelengths for the named colours, and is using the modern ‘blue’ in 1813, but some of his earlier papers of 1801-3 suggest he recognized and had used the older Newtonian ‘blue’ as well.

There are several genetic variations which may shift the green receptor peak by up to 4 nm. The blue peak is pretty much the same for all of us. I don’t think genetic variations are significant here. Different people seem to use different words for colours on the blue-green boundary.

]]> By: Jessica http://www.colblindor.com/2009/08/07/truelight-color-vision-test/comment-page-1/#comment-73901 Jessica Tue, 06 Apr 2010 00:41:04 +0000 http://www.colblindor.com/?p=946#comment-73901 I set my monitor to 6500K like asked. The shades are a little wonky, though. The red is a pinkish-red to be, the green I can't quite describe, and the blue is very purplish. As for seeing them I can make out all bu the last red T, although the fifth is so faint I have to stare to make it out. For the green I can only see up to the third, and once again I have to stare to make it out. For the T I can again only make it out to the third, which is very light. I think I can see the fourth if I squint really hard, but I'm not sure. I've always believed myself to not be color blind, although some people have told me certain things I see as green are blue, but these are colors that are blue-green and I just see them more as green. And yellow greens appear more yellow to me. For example, something such as this towel: http://www.istockphoto.com/file_thumbview_approve/4629406/2/istockphoto_4629406-bar-of-soap-and-blue-green-towel.jpg appear green to me. It is hinted blue, but so faintly I'd never call it anything but green, except maybe sea green. I set my monitor to 6500K like asked. The shades are a little wonky, though. The red is a pinkish-red to be, the green I can’t quite describe, and the blue is very purplish. As for seeing them I can make out all bu the last red T, although the fifth is so faint I have to stare to make it out. For the green I can only see up to the third, and once again I have to stare to make it out. For the T I can again only make it out to the third, which is very light. I think I can see the fourth if I squint really hard, but I’m not sure.

I’ve always believed myself to not be color blind, although some people have told me certain things I see as green are blue, but these are colors that are blue-green and I just see them more as green. And yellow greens appear more yellow to me. For example, something such as this towel:
http://www.istockphoto.com/file_thumbview_approve/4629406/2/istockphoto_4629406-bar-of-soap-and-blue-green-towel.jpg
appear green to me. It is hinted blue, but so faintly I’d never call it anything but green, except maybe sea green.

]]> By: Sarah:) http://www.colblindor.com/2009/08/07/truelight-color-vision-test/comment-page-1/#comment-73192 Sarah:) Mon, 29 Mar 2010 00:21:32 +0000 http://www.colblindor.com/?p=946#comment-73192 I could see the first two of each color. After that gray squares. And I am color normal. I think. I know I have trouble with some colors but, I KNOW I could not be colorblind. But, I could not see past the first two of each color. Weird. I could see the first two of each color. After that gray squares. And I am color normal. I think. I know I have trouble with some colors but, I KNOW I could not be colorblind. But, I could not see past the first two of each color. Weird.

]]> By: Richard Kirk http://www.colblindor.com/2009/08/07/truelight-color-vision-test/comment-page-1/#comment-43194 Richard Kirk Wed, 02 Dec 2009 09:36:08 +0000 http://www.colblindor.com/?p=946#comment-43194 Albedo (comment 4) says: "I see all but the rightmost blue T. But that’s just because my monitor isn’t calibrated." I don't think the monitor calibration is the problem here. The test was designed to be used with uncalibrated monitors, provided the gamma is roughly right for near-greys, and the RGB primaries match the video primaries. I have trouble with the last blue T myself (the colours aren't actually red, green or blue, but I have made them as close as I could to the corresponding primary). For the bottom line, you may need to get closer to the screen so you are using more of your peripheral vision, and defocus your eyes a bit so you are not distracted by your macular vision. Even so, too many people with good colour vision seem to have problems seeing the last blue T. I wonder whether the CIE observer model attributes too much sensitivity to the S (short wavelength = blue) receptor. Albedo (comment 4) says: “I see all but the rightmost blue T. But that’s just because my monitor isn’t calibrated.”

I don’t think the monitor calibration is the problem here. The test was designed to be used with uncalibrated monitors, provided the gamma is roughly right for near-greys, and the RGB primaries match the video primaries.

I have trouble with the last blue T myself (the colours aren’t actually red, green or blue, but I have made them as close as I could to the corresponding primary). For the bottom line, you may need to get closer to the screen so you are using more of your peripheral vision, and defocus your eyes a bit so you are not distracted by your macular vision.

Even so, too many people with good colour vision seem to have problems seeing the last blue T. I wonder whether the CIE observer model attributes too much sensitivity to the S (short wavelength = blue) receptor.

]]> By: Caroline http://www.colblindor.com/2009/08/07/truelight-color-vision-test/comment-page-1/#comment-33209 Caroline Fri, 02 Oct 2009 01:54:40 +0000 http://www.colblindor.com/?p=946#comment-33209 I see 2 ts for protanopia and deuteranopia, and only 1 blue one (i have tritanomaly) I see 2 ts for protanopia and deuteranopia, and only 1 blue one (i have tritanomaly)

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