Cures for otherwise blinding conditions do exist (e.g., cataract removal, some gene therapies for retinal diseases) and they’re good. I have a condition that will eventually render me blind and I would seek to be cured if a cure existed for it.
But pursuing/promoting cures for disabilities, including blindness, is not without problems. See, in the US for example, the politics of the National Federation of the Blind vs. the Foundation for Fighting Blindness. Cures also raise class issues and threaten to further marginalize people who won’t or can’t be cured, for whatever reason. In particular, imagining a world in which ‘everyone’ is cured is dangerous and even inherently harmful ideology.
Also, while I have some reservations about the rhetoric and what I think it likely really means, there are blind people out there who will tell you they don’t want to be cured because it’s part of who they are and they’re getting along just fine. Such people do exist. A similar sentiment exists for some within the deaf community as well.
The reason it doesn’t seem like I was arguing against your comment is that indeed, I wasn’t trying to refute your comment. Reconsider your defensiveness. And bear in mind that not all critiques aim to establish a kind of propositional negation of what they address.