This "directly" distinction you're making is not very relevant.
Usually "direct" would mean that without it, it wouldn't have happened. Yes, whatever broke the glasses would've happened without the glasses as well, but it likely wouldn't have resulted in a scratched cornea. So yes, the scratched cornea is a direct effect of having worn glasses.
You're absolutely right, but the average person does not think like you. Most people don't ever think about stuff like this.
And so you currently have a very "high-level", rational view of technology, that makes it amazing specifically for you.
However, you either disregard or lack contact with people that are (vastly) different. When looking at a technology in relation to the world, like you want to know about in this topic, you have to view the effects on those different people from you as well. And what other people in this thread said is simply observable and happening. A very small percentage uses the internet/technology like you do. The overall effect on the population is not solely amazing.