Basically they look how his eyes were (or glasses) then see how they focus. That's what they did for momma. Hope that helps. Technology is so advanced they can tell so much more than even 10 years ago!

We recently went to eye doctor. Wasn’t sure how it would go. When asked to read line, he would do the first 2 letters and then tried to make a word with the rest of the letters. Doctor then took away all but one letter and highlighted it. That seemed to work well.

Specsavers will come to your loved one - home, nursing home, etc. Boots will too I think.

as he isn't able to really talk properly and really understand often he will just mimic what was just said. wondering how they test babies and maybe there is something available for adults

Having an eye DR that is patient really helps. My husbands vision was the first thing to go...that's when we realized that something was terribly wrong. His eyes were fine, but his brain was not sending signals to the eyes. We went to a neuro-opthamologist , our eye dr. gave him prism lenses which seemed to help some for awhile, but then it was so hard when he couldn't read, watch tv, look at photo albums. He struggled with that for 8 years or so. It was very sad.