cataracts and the brain

Great question! Visual processing includes several different areas of the brain, but primarily the occipital and parietal lobes. You can view this interesting lesson on visual processing if you want a highly detailed explanation.

Since our visual perception is such an important part of processing external information and thereby stimulating brain activity, when vision is disturbed, as with cataracts, it is reasonable to assume a negative effect on some aspects of brain function over time if vision remains impaired. There is interesting research on the positive benefits to cognition when cataracts are removed in older adults, with a marked improvement in cognition, even after many years post-removal, and independent of other risk factors. See this research article by Maharani et al for more information. Best!

My understanding is that supporting vision and reducing strain for the eyes is optimal, though that may come about in many different ways (glasses, surgery, eye exercises, etc.). I would encourage you to speak with your optometrist or ophthalmologist about this to learn if there is greater benefit to do one versus the other long-term. Best!