There are measurable practical differences, besides differences in fMRI responses and pupil dilations as mentioned in the thread, there are also the ones I mention here (https://news.ycombinator.com/item?id=49471908) that involve different skin conductance responses, less response to image priming, less ability to produce image visual details from memory, and etc.

They just aren't obvious practical differences, because cognition or neural plasticity seems so flexible that we can compensate pretty impressively for surprisingly different sensory experiences, overall.