I propose a simple solution to this problem. First, the screen should have a red/purple color offset and a pair of those 3-d glasses so that the important words stick out at them when they are ringing up their merchandise; and second, the earphone speakers on the 3-d glasses should make those old-school 8 bit Atari sound effects (perhaps the 'one up' tone) instead of a monotone beeping noise whenever somebody scans their stuff into the computer. The idea is that through positive reinforcement, these people will become experts at this newfound necessity of life, that is, self-checkout.... either that or they will starve from not being able to buy food when they need it.