Non-fandom-specific explanation: The setting is non-real-world, based mainly on China, with Japanese and Inuit influences, among others. However, inventions that were, in our world, invented in other countries, occasionally show up in this setting, so don't feel limited by that. I haven't decided exactly how old I want a major character to be, which will affect the time period my fic is set in, but the technological level is probably going to be analogous to our world between the 1850s and the 1920s. I know that's a broad range.
Googled: cataract surgery in 1850s China, history of radio (part of how I pinned down the time period), history of cataract surgery, von Graefe cataract, congenital cataracts in adults surgery, idiopathic congenital cataract. I also looked at a post on atla-annotated (a fandom-specific tumblr), which gave some clues as to the setting (though I don't think I'm going to go with the Qin or Tang dynasty dates; neither would fit with the steamships).
1. What results could you expect from cataract surgery during this period? Would it restore vision?
2. I gather that, if someone is congenitally blind, restoring sight in adulthood will not do much good. Exactly how little good will it do, and, more to the point, what could you find out about the possibility if you were researching it at some point between 1850 and 1920, assuming that you have the money, connections, fame and social standing to gain access to any information that's available?
3. I don't suppose there exist any descriptions of either the surgery or its prognosis that were written during the period, but if there are, and you happen to be able link me to them, that would be great.
4. Why wouldn't a rich family with a blind daughter have tried this already? Would historical surgeries have had serious risks? Would it have hurt the family's reputation to admit to having a blind daughter? (Canonically, her existence isn't widely known until she runs away to help save the world.)