What is the colored part of the eye called?
AnswerIris
The iris is the colored ring of muscle that controls the size of the pupil.
Science · Facts & stats
Face facts & stats
7 fact-checked facts about the human face, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
How many teeth are in a full adult set, including wisdom teeth?
Answer32
A full adult set has 32 teeth; children's baby teeth number 20.
Going deeper
What is the hardest substance in the human body?
AnswerTooth enamel
Enamel, the outer layer of teeth, is the hardest substance the body makes.
Which glands produce tears?
AnswerLacrimal glands
Lacrimal glands above each eye produce tears that keep the eye moist.
What is a genuine smile that also crinkles the eyes often called?
AnswerDuchenne smile
Named after French scientist Guillaume Duchenne, it involves muscles around the eyes as well as the mouth.
Expert level
Which muscle closes the eyelids?
AnswerOrbicularis oculi
The orbicularis oculi is a ring of muscle around each eye that closes the lids.
Which cranial nerve controls the muscles of facial expression?
AnswerFacial nerve (cranial nerve VII)
The facial nerve, cranial nerve VII, moves the muscles we use to smile, frown and blink.
Know these cold?Today's round is five questions like these, 20 seconds each. Your streak and level follow you to every arena.Play today's round