Closely related to sunglasses, perving glasses are purchased for the intended use of spying on sexy girls without their knowledge. Perving glasses have dark lenses so that the user can see out, but nobody can see where their eyes are looking, making them ideal for scoping out hot ass and not having to look away when the owner of the hot ass looks at you. They are best used when facing parallel to the girl, while not facing directly at her. The eyes can then rotate in their sockets to focus on the fine details of the girls body.
Lizzy turned to look at Thomas. However, she had no idea he was staring at her sexy ass, as his eyes were hidden behind perving glasses.