Staying up late, long journeys and over-indulging in food and drinks can leave your eyes with a hangover. Lie down and place cold cotton balls or a chilled gel eye-mask over closed eyes for 10 minutes. To get ready for the morning after a big night, soak cotton balls in water, flatten them with your fingers, and keep them in the freezer on wax paper until needed. But avoid drops that claim to take the red out; they work in the short term by contracting blood vessels but can backfire later on, making eyes redder than ever.