I will see if I get this right ...
Book title: Civilization Ends; Surviving Begins
Terrance Bramblett - Post Apocalyptic Earth Fiction.
Available at Smashwords:
https://www.smashwords.com/books/view/71660Most of the world goes blind for some unknown reason. By the time scientists get close to an answer, they too are blind, so society spirals down rapidly. One small group of sighted and blind, led by a decent man, try to escape the chaos of the city for the wilderness. Others groups are not so benign.