11 Jet Lag Prevention Tips That Actually Work

3. Use timed light exposure to reset your clock

Light is the single most powerful cue for shifting your circadian rhythm. That means carefully choosing when you get bright light and when you avoid it. For eastward travel, seek morning light at your destination and avoid bright evening exposure. For westward travel, aim for late-afternoon light and avoid bright early mornings. Apps and simple rules can tell you when to step outside for a 20- to 60-minute walk to accelerate adjustment. Sunglasses are useful when you need to avoid light, for instance, on the morning after an eastbound flight if that light would push your clock the wrong way. Portable light therapy devices can help when outdoor light isn’t available, but try natural sunlight first. Flight attendants and sleep experts agree that day one light exposure is crucial—open your hotel curtains, take a short outdoor walk, and have breakfast during daylight to anchor your new schedule. This strategy is practical and free, and it works because your brain’s master clock responds strongly to the timing and intensity of light.