There are different companies, but I only use Audible. I don't have eyesight problems, I just like them. They help me to fall asleep (I bookmark where I start each night so I can go back if I fall asleep fast) and I use them when I'm doing housework and cooking.
Narrators are hit and miss. You can listen to a sample of each before you buy to see if you like them. I've had a few I hated and returned, there was something stilted and jarring about their reading. Not all services let you return books, and Audible only allow a couple per year.