Colorblindness, colorblindness, colorblindness!

The most popular page on this blog, by far, is one which people are attracted to because of the image of the random dot colorblindness test by Shinobu Ishihara. The two volume publication containing those illustrations, which was printed originally in the 1950s, is rather difficult to find at the major retailers (you know who they are), but those who are truly interested can buy used copies on the Web.

If only brand new will do, there is this place too.

Hope this helps you all.