I have used a Keurig Pro for a while now and it works without a hitch. Makes decent and mostly consistent coffee.

The pods can get a little expensive, but they can be had on sale/in bulk.

As far as I was able to tell from looking at them, the one cup Keurig needs to have water put in each time you want to make a cup. They don't have a reservoir like the multi-cup ones do. Could your brother handle filling up a cup of water and get it into the coffee maker? It actually might be easier to fill a reservoir where the exact amount doesn't matter.

CBTL (Coffee Bean and Tea Leaf) makes an awesome single cup coffee maker. The coffee is always outstanding, easy to use, and the reservoir holds enough water for a coffeeholic's day. We've had one for several years and it works beautifully, no problems. Try the French Roast--unbelievably fabulous!

Any of the Keurigs that have a water reservoir on the side would work well- I think they range 72 to 96 oz for the most part.Your brother could fill it up by feel and operate it pretty easily. WE have the B60 which is nice because the small, medium, and large cup selections are on three separate buttons, not an electronic choice. I programmed it to turn on for us between 7-9 every morning, but you can manually turn it on or off without affecting the programming.

The Keurigs all make single cup serving but the ones without reservoirs that have to be filled everytime you want a cup, are a pain and I would not recommend those.

I am sorry to hear about your brother's vision.
Have you talked with the blind association? They came out and helped my parents set things up around their place.
Also if your brother is a vet, some VA centers offer a vision program called VISOR. It is almost like a camp to learn how to manage low vision. They also gave my dad lots of helpful aids including a computer with a large screen and a reading device. The computer had software to massively enlarge the orint and read it.

Back to coffee
I just bought the nespresso virtuline(sp) for my husband for Christmas.
You do have to order the pods on-line or from specialty shops. The pods are recycled- they give you a recycle bag. It does have a reservoir
Can't tell you much more since we haven't used it other than samples at the store.