I didn't have any vision problems, but I did have one strange experience that might be relevant. On my second or third cycle of carbo/taxol, I had been reading about caloric restriction and its possible benefits for chemotherapy. So the day before my infusion, I decided to cut way back on carbs. I may have overdone it (best I recall I was eating broth with broccoli in it.). That evening I suddenly lost ~90% of the hearing in one ear for no reason. I thought about how the nervous system requires glucose, and I ate some pasta, followed by some ice cream. My hearing was back to normal by the next morning. Since then, I have avoided dietary experiments and have not had a repeat of the hearing loss, despite another 12 cycles of carbo/taxol. So I'm wondering if the keto-ish diet you're on is contributing to this issue.