Color blindness

Color blindness, or color vision deficiency, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions. Color blindness affects a significant percentage of the population. There is no actual blindness but there is a deficiency of color vision. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive color in light and transmit that information to the optic nerve. This type of color blindness is usually a sex-linked condition. The genes that produce photopigments are carried on the X chromosome; if some of these genes are missing or damaged, color blindness will be expressed in males with a higher probability than in females because males only have one X chromosome, whereas females have two and a functional gene on only one of the X chromosomes is sufficient to yield the necessary photopigments.

Color blindness can also be produced by physical or chemical damage to the eye, the optic nerve, or parts of the brain. For example, people with achromatopsia suffer from a completely different disorder, but are nevertheless unable to see colors.

The Yellow and Blue

"The Yellow and Blue" is the alma mater of the University of Michigan, with words by Charles Mills Gayley, on a tune by Michael William Balfe. Gayley composed the lyrics in 1886 while he was a professor of English and Latin at the University of Michigan. He was motivated to write the song in hopes of winning a $20 prize from the student editors of the yearbook (The Palladium). As he wrote the lyrics, Gayley was thinking of the school colors, "azure blue and maize." Ultimately the song became a paean to the color and light of late summer in Michigan: the yellow grain in the fields, the yellow harvest moon, the varying blues of the sky at morning and sunset. These "ribbons that nature has spun" reminded him, too, of "the maid of the golden hair, and eyes that are brimming with blue." Next Gayley chose a soft, wistful melody called "Pirates' Chorus" from "The Enchantress," an opera by the Irish composer Michael William Balfe. Students quickly embraced the song and began to sing it. Leaflets with the words were printed, and within a few years it was, indeed, the University's recognized alma mater. Gayley returned to Ann Arbor from time to time, and in 1925, near the end of a long life, he wrote: "It has always been a great joy to me, revisiting Ann Arbor, to hear the song still sung in fraternity houses, and on the campus in the twilight. I have heard it in mid-ocean, on the streets of Florence and Rome, and hither and yon as I have traveled about the world. A song written in the days of one's youth, if it by good luck expresses the emotion and enthusiasm of succeeding generations of young men and women, is a thousand times more worthwhile than many books of learning."