Even the tiniest of noises automatically makes your pupils change focus.

Even the tiniest of noises automatically makes your pupils change focus

More from the Human Body Facts niche...

Human Body Facts

Most of the time you only breathe through one nostril at a time, and the

Human Body Facts

Your eyes are about 1 inch across and weigh about 0.25 ounce

Human Body Facts

Only one sixth of the human eyeball is exposed

Human Body Facts

Sleep is so important to the brain that scientists believe you can only

Human Body Facts

In your lifetime you will produce around 10,000 gallons of saliva

Human Body Facts

Your body is around 70% water