The Prescription

This Yuppie, being in a charitable mood, picked up a hitchhiker on I-95. The young man was properly in awe of the big expensive BMW. As they traveled along, he noticed a thick pair of glasses on the console between them.

"Are those glasses yours?" the hitchhiker asked nervously, since they were roaring along at about 80 mph.

"Yes, they indeed are," responded the Yuppie. "Wouldn't go anywhere without them. But don't worry," he said, noticing the young man's nervous reaction to the glasses. "My side of the windshield is ground to my prescription."