• Don't drink coffee or alcohol. The atmosphere in any plane is exceedingly dry. It dries out your mucus membranes - mouth and eyes. Alcohol further dehydrates you. Drink lots of liquid - preferably clear, caffeine-free liquid - water, apple juice, ginger ale, 7-Up.
  • Use "natural tears" type eye drops to combat dehydration of your eyes.
  • Bring some fruit in small pieces - bite-sized apple chunks or grapes are good. Fruit is easier to digest than whatever food the airline may provide, and it helps in the hydration process also.
  • Walk around the plane.
  • On your walks, go to the back of the plane. There is usually a little bit of space back by the bathrooms. You can use it to do some standing stretches. If you can, lean against the bulkhead and stretch the back of your legs. Bend over. Squat down. Anything that can help your circulation.