It is hard to tell how long exactly does eye dryness last after the Lasik surgery. It varies from case to case and different people got different feelings about it. It is the most common symptom or side effect after a Lasik surgery, while it subsides as the wound heals up. It is normally lasting from anywhere weeks to months. However about 20% of patients claimed to experience the dryness even six months after the surgery. While according to some reliable resources, about 30-50% of patients taken Lasik surgery experienced dryness of eye for more than one year. And FDA also published an article on their webpage to warn people that Lasik surgery might cause severe eye dryness which might be permanent. I think you'd better take some home remedies to help alleviate the symptom. Drink more water and use a humidifier. Take some nutrition supplement such as flax Seed oil and vitamins. Omega-3 fatty is very good at reducing dryness of eyes, which is rich in salmon, sardines, and mackerel.
First, don't worry. Dry eyes after lasik surgery is not permanent, it will last one to two weeks at most after surgery, only if you observe several tips as below. For example, you should avoid eye injuries by wearing a protective shield at night and with naps until you are advised by your doctor. Also, you should remember not sleep on the side of the operated eye for the first night. And, you may not be supposed to do some exercises after the surgery especially of swimming, it can be very dangerous. Besides, you should avoid the water splashes into your eyes when you wash your face or takes a bath or the dirty water may result in infection. Watching TV or playing computer is not allowed either. What's more, when you go out or stay in high intensity of lighting condition, you should wear sunglasses to protect your eyes. If you can follow all of these tips, you will recovery soon.