I've got bad eyes. I've had operations that improved my vision, but it still isn't good. I can't imagine hunting without a dog. The majority of the hunters here have a nose dog, I'd say 60% or more. It doesn't have to be a bloodhound, some of the best are Dachshund or smaller breeds. In my experience, many dogs aren't hard to train to blood track. The bigger problem is slowing them down. Here they only track on a long leash. My last nose dog was a Weimaraner and could track an almost invisible blood trail at a dead run (somewhere around 40 MPH) if you'd let him, Now I use a Plummer Terrier, they have some Beagle in their genes.