I was thinking of Russia, which was the poorest and most backwards country in Europe when the communists came to power. Within 30 years they transformed it into a military and technological superpower that defeated the Nazis and launched the first human being into space.

Soviet Union, China, Vietnam

Communist governments took power in poor countries and had to endure ‘primitive accumulation’ before they could start building a socialist economy. At best they created workers’ states where employment and basic services were guaranteed to all.

Actually near nearsightedness is due to brightness levels being much indoors rather than focal points. Even on cloudy days it’s much brighter outdoors. There’s also evidence that natural light has a calming effect on people.