Why do polar bears have 3 eyelids?

Related questions

1. Is the blink of an eye faster than the speed of light?
2. Is there a cure for third nerve palsy?
3. Do you blink or breathe more?
4. Can nerve palsy be cured?
5. Do birds have a second eyelid?
6. How do eyelids help the eyeballs?
7. How many minutes a day do you spend blinking?
8. Do reptiles blink sideways?
9. What nerve Innervates the pupil?
10. Is third nerve palsy a stroke?

Tags

1. #protect
2. #third
3. #climate
4. #severe
5. #bears
6. #three
7. #greenhouses
8. #black
9. #eyelid
10. #which
11. #sunlight
12. #helps
13. #means
14. #eyelids
15. #their
16. #polar
17. #absorbed
18. #hairs