[syntheticnature]

It's also worth noting that not all usages of "blind", such as "legally blind", are the same as total blindness. It's conceivable that extremely poor vision (acquired through natural reasons or accident) could be just good enough to allow painstaking circuit construction with a magnifier.

I suppose a breadboard could be done by feel, as well.

Also, I'll quip that I've learned through hard experience not to trust that the red and black wires are used correctly. :-)