1. Not sleeping enough.
2. Not eating enough.
3. Not wearing a hat in prolonged direct sunlight.
4. Not drinking enough water.
5. Spending too much time in front of a screen (computer or TV).
6. Blunt force trauma.
7. Keeping your hair in a very tight pony tail all day long.
8. Wear prescription glasses (that are not your prescription) .
9. Excessive amount of alcohol (this takes time to have an effect.)
10. Falling and banging your head on the ground due to consuming an excessive amounts of alcohol (not water) on an empty stomach, in direct sunlight, while not wear a hat, after staying up all night in front of a screen, while wearing your hair in an extremely tight pony tail and someone else prescription glasses.