If every single person on Earth suddenly became blind, would the human race go extinct?
Lots of people would die in the initial chaos. Like, probably hundreds of thousands.
But we'd adapt.
We've got infrastructure that can be adapted to helping blind people navigate.
Blind people are pretty badass, well, at least most of the ones I know.
You see, you probably have two specific ideas of a blind person: a guy with thick sunglasses following a dog or a lazy person who sits at home like a helpless lump.
They are a wide variety of folk and they can do a crap ton of jobs. They can't drive, but automated vehicles are being researched.
In any case, we'd have trouble for...I'd say, two years.
Lots of people would die in that time. Car crashes, plane crashes, suicide, firearms accidents, succumbing to the local climate due to inability to locate water, and so on and so on.
But humanity would adapt.
We'd probably have military robots within a decade and cane fighting martial arts dojos within five years.
Being blind is, in itself, not fatal. It makes life a little more dangerous, maybe, and changes how you interact with the world - so if we all went blind for some reason, we'd be in the soup, but not in the fire.
And don't forget what it is that humans are best at: adaptation. We adapt to our surroundings, and via technology, we adapt the surroundings to ourselves. People figuring out how to live in the desert? That's adaptation. Terrestrial creatures spending lots of time underwater, even though we don't have fins and gills? We adapted for it. Raspberry Zingers don't grow on trees? That's okay - we'll set up a bakery.
So no matter what happens to make us all blind, the one thing you can count on in the long run is this:
Humans are too damn clever, and too damn stubborn, to give in. We'll find a way.
It's what we do.
Hmmm well, it certainly seems like that - but hear me out.
What if, after the dust has settled and everyone driving a car has crashed, computers have taken over from the (now blind) operators and whichever half of the world was asleep at the time gets a very rude awakening, I personally have hope for the human race.
What if we were to develop a mutually beneficial relationship with dogs that would mean the Dogs acted as our eyes (like modern guide dogs) while we attempted to get society up and running again?
No to the dogs? Okay then, how about this..
Some bright spark creates a program that can take over all jobs that can no longer be performed by humans, and the human race uploads itself into a virtual realm where everyone can see again, exactly (ish) like the Matrix.
No, blind people also know how to function and can function very properly.
It will be very hard in the staring for everyone as the production process will stop and people might starve but they will eventually find a way out of that survive
So yes people will survive but at the loss of many many lives.
No. There are actual blind people who manage to get along quite well with little assistance from the sighted. While most of us would die as civilization collapsed, the species as a whole would not go extinct. Some would survive and develop ways of coping.