More important than the printing press?

I’ve giving midterm exams this week. Giving one right now actually.

When I look around the room so many students are wearing glasses. Several more I know have contracts.

Where would the world be without glasses? Sure the printing press revolutionized the world and helped make the European Renaissance possible, but what about glasses? Have we ever stopped and realized how many people–children, teenagers, senior citizens, people of all ages–wear glasses (or otherwise use corrective lenses)?

I started wearing glasses in 4th grade. Now without my glasses, I am almost blind. I wouldn’t be able to write, read, drive, or anything else the way I do.

When we considered factors that slowed and accelerated technology and human inventions, we need to recognize vision. What we call glasses first existed and became popular from around 1000-1800 CE in very slow stages. Think how much it really influenced society for thousands of years having people who–assuming that human eyes haven’t changed that much per se–simply couldn’t see beginning as children? 

Without glasses the printing press wouldn’t matter.

(Added 7/7/2016: What Did Nearsighted Humans Do Before Glasses?)