Answer: It is really not possible to comment too much with the limited information you have relayed, but there are some things that may be relevant to your situation.
First, LASIK is "lamellar" surgery-meaning that is performed between the layers of the cornea-and under a thin "flap".Whether during a primary procedure or a secondary procedure, such as a LASIK enhancement, there is always the possibility that debris or material can get trapped under the flap. You have described "tear residue" and we are uncertain as to what exactly this is. It could be oily residue-particularly if you have oily skin. It could also be a mucous type material that can also come from the tears-or it could be both. In either of these situations, the material does work its way out or reabsorb, typically with a month or so, at the outside-often quicker. You should begin to see some improvement within 1-2 weeks albeit perhaps slowly. If you do not, it might suggest that there is another type of potential problem, whereby some of the corneal epithelium has actually gotten trapped under the flap in addition to, or instead of the tear "residue". This is a more concerning problem and needs to be addressed by your LASIK Surgeon. If, after 1-2 weeks and certainly after 4 weeks, you are not seeing considerable improvement in your vision, you need to see your LASIK Surgeon for an examination and discuss what steps he or she suggests as this is the time limit that would reflect a prudent observation and self resolution timeframe.