A reader asks:

 I am traveling to a time zone that is 12 hours ahead. I will be in that time zone for 12 days (traveling east to west). If I buy the sunglasses you recommend, how do I adjust the light or what time of day should I wear the sunglasses to overcome jet lag?


You’ve chosen to take on a most difficult challenge, given the huge degree of phase shift you’re trying to make your body do rapidly, and given the tiny chance of finding a non-stop flight for this route. The arduous travel of 30 hours alone makes this a challenge, even without jet lag. For such questions, I usually refer people to the book How to Beat Jet Lag: A Practical Guide for Air Travelers, published years ago by Walter Reich, Norman E. Rosenthal, Thomas A. Wehr, and me. It’s available for just pennies a copy (plus shipping) from Amazon at http://ow.ly/VzVd0. (Disclosure: the book is now officially out of print and the authors no longer receive any royalties.) For the specific trip you mention, you’ll want to avoid light before 10 AM on the first day of travel. From 9 PM – 3 AM (original time zone) you will want to stay awake and expose yourself to bright light. This will be a challenge because of the late hours when your body will likely be doing its best to drag you off to sleep. At 3 AM (original time) reset your watch to the destination time zone. Then after 4 pm (destination time) avoid light again. This is the start of inducing the phase delay that you will want for your westward travel. Your “time-light” efforts will continue for the next three days at your destination, and those details along with critical caveats and safety guidelines are detailed in the book I mentioned. ―Dan Oren, MD