I don't know what causes the watery eyes after lasik surgery. But it is normal to watery eyes after the lasik surgery. But it is just temporary. Nevertheless, you shall not touch your eyes under any condition even if the eyes water a lot. All you should to do is to let your eyes rest and do not wear contact lenses in this time. If you suffer very serious pain after the surgery, you must contact your doctor at once.
Generally speaking, it would be normal for you to have watery eyes because a lot of people do the same. Anyway, it is one of the lasting impacts after the surgery and may you have got some dirty water splashed in your eyes or you have rubbed your eyes, which could lead to watery eyes or infections. Just try to examine your eyes again and take measures.