I had Lasik surgery in January 2001. A few days ago, I noticed a greenish gray shadowy circle in the middle of the line of vision in my right eye. My vision is still clear through the circle, but light is definitely dimmer. It is most noticible against white backgrounds and at night. Is this a "central island"? Thanks so much!

You are probably seeing a floater, and as such, you should see your own eye doctor immediately. Floaters are very common in people who are (or were) near-sighted. The concern is that they are associated with a retinal hole or retinal detachment, and thus require an immediate exam with your own doctor.
Central islands can not pop up months or years after LASIK.
I hope this helps.

I believe you are asking about LASEK (not LASIK) which is a variation of PRK where the epithelium is replaced at the end of the surgery. The results seem to be atleast as good if not better with LASEK than PRK, although some doctors feel there is no diffference.
In general, the results of PRK are similar to that of LASIK at the one month, 3 month, and one year visits in many studies and also in my own experience. The advantage of PRK over LASIK is that no flap is needed. But the disadvantage is that it takes a few days for the vision to recover with PRK/LASEK versus often the next day with LASIK. As well, there is more discomfort over the first few days with PRK/LASEK as compared to LASIK.
I hope this helps
Best of luck

Bill Trattler, MD
Miami, FL