An extra pair of glasses and a sufficient supply of any drugs you take regularly or might need. Minimize or avoid consumption of alcohol or caffeine drinks on the plane. They dehydrate you and can worsen jet lag. Drink lots of water and juices and try not to go to bed immediately when you arrive. This will help reset your internal clock.
Some medications reportedly can help counteract jet lag.
One is Halcion. Consult your physician. But a word of caution. This is the drug that President George Bush reportedly took before his projectile vomiting in Japan. Don't drink the water.