Responses
People don't realise this type of vision issue can happen irl. Basically the poison has weakened his eye muscles so he'd really have to force himself to focus to see properly. It likely takes up a lot of energy and causes physical pain to do it.
I have astigmatism in my left eye and my right over compensates to fix the issue. So if I want to focus on reading it is really difficult and I get massive headaches. So this is why I assume his vision is how I described it.
I guess people thinks he's really blind. He ingested some poison but not all of it, so he's partially blind. Sometime he can clearly see but blurry most of the times. He literally said it.