Maybe i can help. I had LASIK years ago. It got me to 20:25. With glasses I see 20:15 so I still wear glasses.
At 40 the need for readers came along. Now I wear trifocals. I've had many conversations with eye docs about shooting a bow. Progressive lenses only focus in the center. Stinks for hunting and shooting a bow because the corner of the lense you look through to see your pins isn't in focus.
I now have a special set of glasses just for shooting a bow. There bifocals, long range on the top and readers on the bottom. I sat with the tech at lense crafters and told him what I wanted. Full focus horizontally across the lenses, long range top, readers on the bottom. He told me I can make it but I can't give you the 12 month replacement if you don't like it policy.
I walked out with them.
Long story short, the reading lense is just a sticker that they somehow adhere to regular glasses. Your brother needs a clear lense on the top and readers on the bottom. He'll never be able to have perfect focus on both the sight pins and the target but you adapt and at least you can see that your arrow is knocked and look at your watch.
And I agree get a prescription for the correct reader lense, it makes a world of difference.
Also I've found fewer pins makes it easier to focus.
Oh and there not progressive so the line will show :)