Oh poor thing.
She's had a bit of a rough time.
If she is going blind she'll be able to cope - it's not the end of the world. You may have to make adjustments for her, and she certainly would not be able to go out - but thousands of cats live as indoor cats and love the life (you should see our girls pout when they have to 'go out to get fresh air' in their runs!).
If she had a cataract I would think her eye would be milky. Does it look as it always has?
Whisk her off to the vet. It's probably something and nothing, but you need to make sure.