Also, I didn't know that the safari handled 2000 people an hour. I guess that would be a lot of goggles for Disney to sterilize. But, they have to sterilize the glasses for the AKL safari not to mention rides like TSM and Star Tours, no biggie -- it's not brain surgery, lol.
The 3D glasses for Tough to be a Bug, TSMM, Star Tours, Muppets etc just go through a dishwasher machine, really easy to wash.
Night Vision goggles are electronic, so can only be wiped down with a cloth or wipe, a much more labour intensive job. So for 100 people a day on the AKL exclusive safaris it is easy. Also if they are more like binoculars (which I think the ones used on the overlook at the hotel are) then don't need cleaning at all really. However with the risk of damage and theft when unsupervised, they would never be used in a high throughput attraction.