Which part of the human eye controls the size of the pupil?

More Questions:

Which chess piece was originally called "the elephant"?

What kind of creatures are Nag and Nagaina who plan to kill Rikki-Tikki-Tavi in "The Jungle Book"?

For whom did Robert May write the story of Rudolph the Red-nosed Reindeer?

What is the only US state with four consecutive consonants uninterrupted by spaces?

Which US state is home to Petroglyph National Monument?

Which state-chartered university is located in a town called Chapel Hill?

Ouranophobia is a fear of what?

What is the title object of the 2006 film "Brick" a brick of?

In what city do The Simpsons live?

Who wrote and also starred in the 1980 movie "The Blues Brothers"?

What year saw the release of the movie "Back to the Future"?

Which US president lived in Montpelier?

What explorer was the first to sail around the southern tip of South America, and name it Cape Horn?

The US Midwest experienced a severe drought known as the Dust Bowl, during what decade?

What is the common name for the condition dyspepsia?