-An 1883 study of military recruits found myopia was much higher in students and merchants than farmers -A 1969 study of Eskimos found that myopia had increase

-An 1883 study of military recruits found myopia was much higher in students and merchants than farmers -A 1969 study of Eskimos found that myopia had increased dramatically since Western schooling was introduced -A 2012 study of German students found more than 50% of university graduates had myopia vs. 25% for dropouts -In countries like Singapore and Taiwan, myopia is common among even young school children They all fit in the "correlation does not imply causation".