Interesting. I'd never heard of that before. I wonder if the blind fans are typically the ones who were born without vision, or the ones who lost it during life. Because I can't really imagine how you'd visualize a game in your mind if you'd never seen one ever.Vusually impaired people get a little radio when they enter the ground.
It must be a love of the atmosphere as well (cue the there's no blind City fans jokes)