I have had an Audible subscription for many years and, more recently, have supplemented my listening with books from Borrowbox. Like you, I love to read but ageing eyes makes listening a good alternative. Also, I like to listen on the go when out walking, gardening etc.
My only gripe with Borrowbox is that licensing restrictions mean there's often a long wait for many of the books I'd like to listen to. I believe libraries may only be allowed to loan out a restricted number of copies at a time. I think I have found a workaround though. When a book becomes available, I download it, copy it to my iTunes library then return it immediately, freeing it up for someone else to borrow. The book stays in my library to listen to at my leisure.
Also, I've noticed that the audio versions of the latest fiction releases are being broadcast as Book of the Week or Book at Bedtime very soon after the release of the paper version has been published so worth keeping an ear on the Radio 4 schedules.