There was an interesting item in Discover site by Nina Bai on Oct 28. Apparently tennis refs are biased in the direction of their calls. They make many more mistaken out calls than in calls. This is the result of an illusion. The refs like everyone else anticipate the motion of an object. Dr. David Whitney had the idea of testing the calls while watching Wimbledon.
The visual system is sluggish It takes a hundred or more milliseconds for us to become aware of an image that strikes our retina. If the object is moving fast, the brain produces an illusion that the object has moved slightly further than it actually has in order to overcome this lag.
This is another example of our consciousness predicting into the very near future.