Yes. What I meant is that in the absence of such perfect knowledge (whether dementia causes poor vision or poor vision causes dementia), which is usually the ca

Yes. What I meant is that in the absence of such perfect knowledge (whether dementia causes poor vision or poor vision causes dementia), which is usually the case[1], we can pursue these strategies anyway because the nervous system learns by association and by introducing a perturbation to its inputs, it could adapt toward our goal. [1] Because the brain and body is a huge complex system and it's hard to untangle cause and consequence: There is usually no single cause and a lot of feedback cycles where the consequence could reinforce its cause.