What can I do to help a person who has had his cataracts removed?

Postop. Transportation, putting in eye drops, getting new glasses. Usually someone sees well fairly soon after cataract surgery and thus does not need as much help as compared to other surgeries.
Post op care. Hopefully very little! many post-op cataracts patients experience near 20/20 vision. They must take their drops afterwards which you may help with. Overall, this is a very satisfying procedure which restores independence.