We once had a beautiful Labrador girl who had been rejected from the guide dog training programme due to her eyesight not being perfect in one eye. She was about 14 month old when we adopted her, and she lived many happy years with us until she reached 12, and finally crossed over the Rainbow Bridge. She had a few mishaps along the way, mainly caused by her walking or running into things on her left side due to reduced vision, but she was the most faithful and Loyal companion you could ever wish for.
My Daughter, who was a teenager at the time, now has a family and a Labrador girl.of her own. Again she adopted a rescued dog, but from someone local this time who was unable to take their pet with them when being rehoused due to a Marriage breakup. Again you could not wish for a better behaved dog, so loving and faithful too. It must be a Labrador trait though, as she too has had eye problems for the last couple of years which started around the time she turned 8 years old. She's fine around the house, and in places she knows well, but we first noticed it when she started to jump into the Hatchback of the car before the hatch was open for her to do so, resulting in her banging her head.
She now has a younger housemate, an 8 month old Cocker Spaniel girl, but she's crazy, acts first and questions later, so boisterous that she's just had to have surgery on her knee joint, where the get has spotted further hereditary problems in her hips which will require surgery at a later date. Thankfully they do have pet insurance, but it costs them £40 a month for the Spaniel alone.
I'm not planning to have another dog due to my own mobility issues, but if I did, I would probably go for a small smooth coated Lapdog, much less to clean up after them when out and about, cheaper to feed, and you can easily pick them up and carry them in a shoulderbag if needs be and you train them to do so! Much less of a distance needed to walk them too. I quite like the small Chihaua smooth coated Girls, or even something my Grandaughter has, a fully houstrained Jack Rabbit, who thinks he's a Dog!