Tears

eyes · body systems · water

Four types of tears. Your eyes make different kinds of tears for different jobs. Basal tears keep your eyes wet all the time, reflex tears wash away irritants like onions or dust, emotional tears come when you're sad or happy, and closed eye tears happen while you sleep.

Made by tiny glands. Tears come from lacrimal glands tucked near your eyes. These glands are so small you can't see them, but they work all day and night to keep your eyes comfortable.

Secret recipe. Tears aren't just water. They're made of water, salt, proteins, oils, and other special ingredients that work together to protect your eyes and help you see clearly.

Can increase fast. When something irritates your eyes, your tear glands can make tears about 100 times faster than normal. What usually comes out as a tiny amount can suddenly become real tears that roll down your cheeks.

All land animals. Every mammal that lives on land, from elephants to humans to your pet cat, has lacrimal glands and makes tears to keep their eyes healthy.