Colorblindness
How I See The World
I am colorblind. Now, thanks to some nifty software I found, you can enjoy an electronic simulation of how I see the world! Trying to explain what it is like to be colorblind is nearly impossible since I have no idea what it is like to have true color vision. Thus, the best way to learn about it is through colorblind simulations. On with the show!
The three sets of images of my friends below give a comparison between normal vision and red/green colorblindness. The images on the right are the colorblind simulations.
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| Normal color vision |
Red/green colorblind simulation |
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| Normal color vision |
Red/green colorblind simulation |
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| Normal color vision |
Red/green colorblind simulation |
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| Normal color vision |
Red/green colorblind simulation |
As you can see, I don't view the world in grayscale. A colorblind person can view every color frequency that a normal person can see. The problem is that defects in the eyes' rods cause some frequencies to change intensity. This causes some distinct colors to appear similar.
A common way to diagnose colorblindness is an Ishihara test. Most people who view an Ishihara plate can see a pattern among the colored dots. However, a colorblind person will find it difficult, if not impossible, to distinguish a pattern. In the example below, a standard Ishihara plate is shown on the left. Most people will see the digit 3, but a colorblind person will see the plate as it appears in the simulation on the right.
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| Normal color vision |
Red/green colorblind simulation |
Try the following tests to see if you can correctly identify colors in a colorblind simulation. The images shown are colorblind simulations. Take a good look and decide the colors of the car and flower. To reveal the true color, place the pointer over the image to show the true colors.
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| What color is the car? Yellow? Green? Place the pointer over the image to remove the simulation and reveal the car's true color. |
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| Is that flower really blue? Place the pointer over the image to remove the simulation and reveal the flower's true color. |
More than likely, you'd have never guessed that car is really red. This is the difficulty of colorblindness. However, colorblind people do have ways to compensate for their disability. Personally, I could tell with great certainty that the car is red, despite the fact that it also looks green. I'm not always sure how these compensation mechanisms work, but they do exist. For instance, when I'm asked to count the number of colors on, say, a sign, I may not identify all the distinct colors, but I'll correctly identify many more than a color seeing individual viewing the same sign in a colorblind simulation. Most compensation techniques are based on logic. If, for example, I see a dog that appears green, I'll decide it's brown because I know there is no such thing as a green dog. Also, if I see a man wearing what appears to be a light pink shirt, I'll assume the shirt is actually grey because men don't often wear pink. There are some cases in which compensation techniques offer no refuge. Such is always the case with the color purple. I'll almost always identify the color purple as a shade of blue.
Check out how I see a rainbow. The only band that is obvious is yellow. The reason for this is that the rods which are sensitive to yellow are unaffected by color defects. So, if you want a colorblind person to notice something, paint it yellow!
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| Normal color vision |
Red/green colorblind simulation |
I should also mention that yellow fire trucks attract my attention much faster than red ones (although I do find red more aesthetically pleasing, but that's not the point). Imagine my confusion growing up hearing that emergency vehicles are painted red so they are easily noticed. Ridiculous! Red is a good way to camouflage a vehicle to a colorblind person. Yes, I have been known to run a stop sign every once in a while! That brings me to the subject of stoplights.
The most common query I encounter is, "if you can't tell the difference between red and green, how do you respond to traffic signals?" Simple, the red light is always bigger and on top! Actually, I don't even do it that way. Not only does color matter, but intensity. The red and green lights look very different (as can be seen below) because the green light is so much brighter than the red light. If the red light were equally as bright as the green light, there would be much trouble. Actually, there is an abnormally bright red light in Joliet. I've been known to run that light at night much to the dismay of color seeing passengers! Yes, some insurance companies charge colorblind drivers higher premiums.
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| Normal color vision |
Red/green colorblind simulation |
As you can see, it's not hard to differentiate between the colored lights. Single flashing yellow or red signals do present a confusing situation in some lighting conditions, though. In that case, I always assume a flashing red and come to a stop. True, I've received many a rude gesture from following drivers for stopping at a flashing yellow signal, but I'd rather make someone three seconds late than take chances.
I won't go into the physiological details of colorblindness. There are plenty of good sources for that information, and I have listed a few below. For now, I hope you were able to learn a little bit about colorblindness through the experience of simulations.
For a more rigorous explanation of colorblindness, please visit the following links.
