Why do cats have vertical slit pupils?

To control light and judge distance for ambushes

Why are white cats with blue eyes often deaf?

A gene linked to both affects the ears

Why can't cats see well very close up?

They can't focus closer than about 30 cm

The Cat Eyes Quiz – Facts Worth Knowing

A cat's eyes shine in the dark because of a mirror-like layer behind the retina, and the cat eyes quiz explains how it works. Learn why cats have vertical slit pupils, how eye color develops, why white cats with blue eyes are often deaf and what the third eyelid does.

Start the Cat Eyes Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Glow
What makes cats' eyes glow in the dark?
Slit
Why do cats have vertical slit pupils?
Field
How wide is a cat's field of view?
Colors
Which colors do cats see poorly?
Blue
Why are white cats with blue eyes often deaf?
Third
What is a cat's third eyelid called?
Change
When does kitten eye color settle?
Colors list
What is the most common adult cat eye color range?
Mood
What can sudden pupil dilation signal?
Close
Why can't cats see well very close up?

Explanations: answer key for all 10 questions

Q1: What makes cats' eyes glow in the dark?
Answer: The tapetum lucidum
It reflects light back through the retina.
Q2: Why do cats have vertical slit pupils?
Answer: To control light and judge distance for ambushes
Slits close tighter than round pupils.
Q3: How wide is a cat's field of view?
Answer: About 200 degrees
Humans see about 180 degrees.
Q4: Which colors do cats see poorly?
Answer: Reds
They have fewer cone cells.
Q5: Why are white cats with blue eyes often deaf?
Answer: A gene linked to both affects the ears
Odd-eyed cats may be deaf on one side.
Q6: What is a cat's third eyelid called?
Answer: Nictitating membrane
It protects and moistens the eye.
Q7: When does kitten eye color settle?
Answer: Around 6 to 8 weeks or later
Final color may take months.
Q8: What is the most common adult cat eye color range?
Answer: Green to gold
Blue is mainly in pointed breeds.
Q9: What can sudden pupil dilation signal?
Answer: Excitement or fear
Light also changes pupils.
Q10: Why can't cats see well very close up?
Answer: They can't focus closer than about 30 cm
Whiskers help instead.

The Cat Eyes Quiz – Windows of the Night Hunter

Cats have large eyes built for hunting in dim light. Behind the retina, a reflective layer called the tapetum lucidum bounces light back through the eye, improving night vision and making cats' eyes glow in photos and headlights.

Vertical slit pupils can open wide in darkness and close to thin lines in bright sun, and they help ambush hunters judge distance. Cats have a wide field of view but see fewer colors than people, and they struggle to focus on objects very close to their faces.

Kittens are born with blue eyes that change to green, yellow, gold or stay blue in some breeds. White cats with blue eyes are often deaf because of a linked gene. Cats also have a third eyelid that protects and moistens the eye.

What This Quiz Teaches

Cat lovers and science students will enjoy these questions.

Why cats' eyes glow
Why pupils are slits
Which colors cats see
Why some white cats are deaf
What the third eyelid is

Did You Know?

Cats blink less than humans.
Odd-eyed cats are called heterochromatic.
Siamese have blue eyes due to genes.
Cats see motion very well.
Dilated pupils can also mean pain.