Knowing there is a good deal of interest - on this list - in inherited "defects" I thought I might just toss in a couple of things I happened to pick up about "colour blindness." After WWII, because of the development of the electronics industry, there was a lot of research done into color blindness, mostly resulting in improvements in our ability to detect and "measure" its effects. Certainly, red/green is the most common form but there are an almost infinite number of other color combinations that various people have difficulty distinguishing. So much so that (and this may be just hearsay) that it's possible that the majority of people are "color blind" in some way or another. Now I put "color blind" in quotes here because this includes perception difficulties in distinguishing one shade of a color from another, because - in the strictest sense - this is still color blindness. Fortunately there is far less reliance on color coding in the electronics these days, so work in the industry is not precluded to nearly as many as it used to be. One of the neatest color blindness tests I have ever seen consisted of a simple pack of cards, except they were not printed like normal playing cards each, instead, being a mass of colored dots. The colors of the dots and the pattern of them was carefully contrived so that depending on your particular version of color blindness you would be able to - or not - see a number made up of some of the dots - or even to see different numbers on the same card depending on your particular color distinguishing impediment. It was years ago that I saw these so I don't remember all the details, but I do know I was surprised to find out I was blind to one of the more subtle color combinations. It had never caused me any difficulties - nor has it to this day as far as I know, and I'm sure the knowledge might have been useful - if I hadn't forgotten it almost immediately! :-) On the other hand it might account for those endless "its blue / its green" arguments Chris and I have had about that strange shade of aquamarine. :-) Anyway, the point is that color blindness is not some rare, exotic, condition. There's a good chance you have it. And as to it being hereditary - if you are a member of the human race then yes, you probably have inherited the gene! As an afterthought to this message - I believe I was living in England when all this happened. It hadn't occurred to me before that this could be just a "British" condition but perhaps I should add a "your milage may vary" rider that I have no similar experience here in Canada - although I can't imagine why there would be a significant difference. Malcolm Archive CD Books Canada Inc. President: Malcolm Moody PO Box 11 Manotick Ontario, K4M 1A2 Canada. (613) 692-2667 WEB SITE: http://www.ArchiveCDBooks.ca > Date: Wed, 11 Jul 2007 19:13:39 -0400 > From: "Georgiana Webster" <wwebster5@tampabay.rr.com> > Subject: [CAN-ONT-SIMCOE] color blindness > To: "SIMCOE" <CAN-ONT-SIMCOE-L@rootsweb.com> > Message-ID: <002401c7c411$1f632d70$1ba7c844@S0029820157> > Content-Type: text/plain; charset="Windows-1252" > > Apparently color blindness is most common in the red and green colors. > > During World War II I knew two brothers (twins) who joined the > R.C.A.F. The one became a pilot, but the other, due to having color > blindness was in ground crew, and maintenance of the the planes. > Just a note of interest - I hope, to some people. > Georgiana