Jim looked at his cat's eyes on a bright sunny day, then he looked at the eyes when the cat was in very low light inside the house. In the high light condition, the cat's pupils well be
smaller. larger
A B
The pupil automatically gets bigger or smaller to let more or less light in as needed.
let more light in
bigger
more
MORE
MORE
gets bigger
low light
sunny
pupils
inside the house
day
day