I just found out, via my oldest daughter, that my mother, 92 and living alone, had some eye surgery . She took a taxi there and back. But I am concerned that she is hiding things from us and don't know how to address this. She is in avoidance about her age---she wanted a new car this summer!
Without "prying" or making her defensive it sounds like it might be time to increase the casual communication you have with her and try to keep abreast of what is going on in her life. If she had cataract surgery there is a schedule of eye drops that must be applied for several days. Most people would appreciate some help with that. The trick is offering help without getting her dander up and causing her to be more evasive. If you get that honed to a science, come back and let us know -- lots of us could use help with that!