[recycled sixtie]

Now that Alex has answered as a professional this is what my mother experienced in the UK. I am sorry to hear about your wife's eyesight. I am not an eye prof!

Back about 15 years ago my mother was diagnosed with glaucoma. She took drops and had an operation in each eye. She passed away four years ago age 94. She never became totally blind but her last home was a home for the blind and she paid for this privately.

The most obvious deficiency was coming out of a restaurant with her. I had to take her arm and guide her out. Coming out of a dark restaurant and into bright sunlight her depth perception was poor especially when she had to descend steps. She seemed to be able to read quite well in her later years and she did like to read.

I go for yearly eye checkups and so far age 70 I am glaucoma free.