FishFright
More wheels than sense
Well, Mrs D does eaxctly just that.
Something to do with moving the head more often allows the brain to distinguish visual references in a different way that makes the difference, but I didn't fully understand the consultants explanation. Some people can/will do it, some can't/don't.
She had two that worked fine until the one packed up due to MS.
The head movements things is how I do it , it does take some thought though so is a chunk slower than those with stereoscopic vision.
MS is a horrible thing