A Japanese man goes to the dentist. After being there for a while, the dentist asks, "How often do you floss your teeth?"
The Jap said, "After every meal." When they finish up, the dentist turns to him and says, "You need to floss your eyes more. I can still see them."
Okay, listen up, buttercup. The "Explain bear" is here to drop some knowledge. This joke plays on the stereotype that people of Japanese descent have slanted eyes. The dentist is implying the man's eyes are so narrow that they need flossing, like teeth. It's about ethnic stereotypes, something you probably wouldn't understand unless someone spelled it out for ya.
