Book 1, Question 20
Why Do We Cry Tears? It's More Than Just Water!
Tears do more than show feelings! They wash away dust and tiny bits to keep your eyes clean and protected. Your brain also sends out tears when you feel sad, happy or overwhelmed, and those tears can bring relief. Tears are not just water: they have salt to help fight germs and a little oil to keep them from drying up too fast. Onions cause reflex tears too, when a gas tickles your eyes.
From the book
Page from A Million Whys Book 1
More fun facts
- Your eyes make three kinds of tears: basal tears, reflex tears, and emotional tears.
- Basal tears are on duty all the time. They keep your eyes wet and wash away dirt.
- Reflex tears rush in when something irritates your eye, like a grain of sand.
- Each tear has three layers: oil, water, and mucus. The water layer is the thickest.
- Tears help focus light so you can see clearly.
- Used tears drain through tiny tear ducts into your nose.
- Emotional tears contain chemical messengers like acetylcholine.
- When you cry, your tear glands make tears faster than the old ones can drain away.
Sources: Cleveland Clinic, Cleveland Clinic
Questions kids ask
Are all tears the same?
No. Basal tears keep your eyes wet all day, reflex tears wash out irritants, and emotional tears come with strong feelings.
Where do tears go after they wash your eyes?
They drain through tiny tear ducts into your nose.