19, 20 & 21
19. Get your eyes checked. Some headaches are caused by eye strain. If you work at a computer a lot, you may need to have computer glasses as well as other corrective lenses.
20. Avoid bright lights and always wear sunglasses when you’re dealing with a lot of glare.
21. Avoid known allergens or get tested for allergies. Allergies just don’t make you sneeze or break out. Sometimes allergies result in headaches.