<<Disclaimer: Verify this information before applying it to your situation.>> Color blindness (listmates were wondering if it's potentially celiac-related) can be diagnosed through the "Ishi Hara" (ee-she ha ra) test (that's the name of the person who invented the test).... it's the circles of color that highlight different color shades.... if you have color blindness you will see a different pattern of numbers within the circles then a person who does not. They had these at a science fair & my husband's color blindness was real clear- he was seeing different numbers then the rest of us were! It runs more predominently in males. Looking at paint swatches together is always loads of fun! fran