Change blindness refers to the frequent inability of your visual system to detect alterations to something staring you right in the face. Since far more information lands on your eyes than you can possibly analyze, the brain screens visual stimuli using bottom-up or top-down attentiveness. Bottom-up (e.g., wildly waving hand) can get your attention because it sticks out. Top-down is a volitional act where you turn your “spotlight” of attention toward something specific (e.g., finding your suitcase on an airline baggage carousel). (Angier, Natalie. Blind to Change, Even as It Stares Us in the Face. April 2008.)

Less than 2% of the population has some form of color blindness in the U.S. (National Geographic. “The Smell Survey, 1.5 million participants.”) (Gilbert, Avery N., and Charles J. Wysocki. p 514. Washington D.C.: National Geographic Society, October 1987.)

The X chromosome carries all genes for red/green color vision. Only 1 in 230 females is born with red/green color blindness; 1 of 8 males has some red/green color vision deficiency. (Fisher, Helen, PhD. The First Sex. p 90-91. NY:Random House, 1999.)