Are cats and dogs really colorblind?

As Cecil Adams observes in The Straight Dope cats and dogs are not completely colorblind but one can compare their vision with the vision of human being suffering from Deuteranope. The same is reported from Earth & Sky and as I read through my conclusion is: They are just not interested in colors. In their lifes there are much more important things to do then to distinguish different shades of color. Maybe it’s the same for us colorblind: Just more important things to do than spotting red flowers in a green field or learning that the sky is blue even if it is gray all day long these days. I would say we can concentrate much better on our work and don’t get abstracted by seeing our world full of colors. We get the work done!

Colorful Houses

This picture was taken about one and a half year ago in Locarno, a village in the italian part of Switzerland. I think those frontages show some very nice colors. But see yourself if you can spot any differences.

Colorful Houses - OriginalOriginal Image
Colorful Houses - ProtanopeProtanope Simulation
Colorful Houses - DeuteranopeDeuteranope Simulation
Colorful Houses - TritanopeTritanope Simulation

No differences or all completely different? To me the original image and the protanope and deuteranope simulations look almost the same. The deuteranope one is maybe a little bit more pale. And the tritanope simulation looks almost like a greyscale picture to me.

Olympic Wintergames Recap

The games are over. Torino is going back to daily business. Efforts to spot the difference between gold and bronze medals are diminishing. What lasts is:

  • Curling is very nice to watch. Particularly because the stonecolors for the two parties is yellow/red and not green/red, great to distinguish. By the way is great to learn and see in action the curling – well – basics.
  • Left – right – left … stands for slalom. The poles are blue and red alternately. Most of the time I can’t see which is which. But maybe it’s more because of their speed than my color blindness.
  • Ice hockey teams are tough. And I could always distinguish the two teams. I remember a time when the dresses weren’t always so far apart from each other in my eyes.
  • And short track is fast, very fast and wasn’t shown enough on our tv stations.

By the way, Switzerland finished on the 8th place counting medals with 5 gold, 4 silver and 5 gold medals.

Khaki – the Color of the Colorblinds

If you are colorblind and are looking for a new job choose either hunter or soldier. According to the article “In Combat, Stick with the Colorblind” in the latest issue of Discover Magazin you could belong to the top in one of those prefessions. English scientist discovered that colorblind people are much better in distinguish different khaki colors. And out of that they concluded, that colorblind people make good hunters or soldiers. I never hunted but I was in the army, it’s compulsory in Switzerland. We were wearing those funny clown costumes and sometimes we were even digging through the mud. Personally I never thought I could make out my counterparts and just because of my color blindness I was definitely not a better soldier. The scientists even hypothesize that we colorblind are a revolutionary relic because we can spot predators or hidden food. This makes me feel good – being a bit closer to our ancestors and not only being handicapped but even have an advantage over the not colorblind under us.


I just adjusted my favicon. Can anybody see anything? Because – I can not. I mean, I can see the circle but no number. And you should see one inside the circle. Maybe it is just a bit to small.

Simulating Color Blind Vision

Do you want to simulate a color blind vision? Go to Vischeck and try it online. You can find out what an image or a webpage looks like if you suffer from Deuteranope, Protanope or Tritanope. I think this tool is just great and for me I often can’t see any difference between the original image or the simulated images neither for Deuteranope nor for Protanope. On their webpage you can even find a PhotoShop plugin to download for free. The plugin offers the same image corrections as described above.

A second but for us color blind people even more interesting tool is the online Daltonize of images. Daltonize tries to correct images for color blind people. You can adjust a red/green stretch factor (Deuteranope and Protanope), a luminance correction and a blue/yellow correction (Tritanope). Give it a try and see what you maybe can’t see yet.

What the Doctor says

In the words of my doctor:

[…] suffering a total color blindness with a very strong protanopia […]

And what does this mean? Wikipedia discribes the different kinds of color blindenss in detail. If I read through this article I’m not sure if I suffer just under protanopia or under deuteranomaly and protanopia. Hmmm. I remember he showed me many many circles in a thick book which was split in two parts. In the first part I could see on the first four pages the numbers (you have to recognize numbers inside the circles; they are shown in a different color). Then nothing. He browsed through at least 20 more pages and stopped again in the middle of the book. I look at it. Yes, I see the number and on the next page – nothing. And so on. Maybe the first part was for protanopia and the second for deuteranopia? I don’t know. Anyway, this was over 10 years ago. If I look these days at some example pictures I often can’t recognize any difference for both characteristics. So I would say I’m quite handicapped :-)

Olympic Medals

Olympic Wintergames 2006 in Torino, Italy. Right now athlets from all around the world are fighting for medals. My question is: Can you tell the difference between the gold and the bronze medal? I never can and never ever could. You really have to watch very closely and carefully if you want to see the difference. Otherwise you just guess, read the caption or just let it be.

But anyway, Switzerland has until now 4 gold, 3 silver and 4 bronze medals thats the 6th place on the medal tracker. And in about two hours it will be one more, silver or even gold for the women’s curling team. That’s pretty cool and the games are not over yet!

Update @ 16:25 : Just in this moment I hear that we have won one more gold medal in women’s parallel giant slalom. That makes 5 gold, 3 silver, 4 bronze.

Going to the Toilet

Actually the thing I hate the most is going to a public toilet, or the toilet at work, just any toilet which has this little nice helper just below the handle: green means available and red is shown if it is occupied.

Now think of this situation: You really have to go to the toilet. Finally you can find the public toilet which has 100 toiletboxes. All doors are closed. You pass by to search the one and only which is available. Ok. With a normal color vision, you just rush along the boxes and turn the last green to red. And me? I walk along and recognize, that I can’t see the difference between available and occupied. I look closer, but no way to see any difference. I start listening, maybe I can find the one. Finally I start pushing every, really every handle down to find my way through to the green-one with people yelling at me: “Hey man, cant you see, it is occupied.” Just to finally find out after a long walk that none of them is available.

Yes I know. It’s not like that. But almost. Really. I walk pass the doors and try to find out which ones are occupied and try to find the available ones. I’m always relieved if doors cant be closed if they are not locked or if it is written down in small letters: occupiedavailable.