I noticed the last time I was there that there is a 2 line LCD display on the park side of the turnstyles that indicates the type of pass you are using (AP, Park Hopper, Child, Adult, etc), how many time's it had been used that day, and, I think, the number of day's left (or used - hard to tell) on the Park Hopper. Net is they don't have to look at the pass to tell what it is. They just choose not to care.