The first laser system to correct farsightedness has won recommended approval from the government's scientific advisers.

Visx Inc.'s laser already is used widely to correct nearsightedness, the inability to see clearly at a distance.Advisers to the Food and Drug Administration voted unanimously Thursday that the laser appears also to help mild to moderate farsightedness, or difficulty in seeing objects at close range. The panel was split on whether Visx provided enough data to prove it helps severe farsightedness.

The panel did set conditions for approval. Expressing unease about the stability of patients' eyes after surgery, advisers urged the FDA to require six months of follow-up data on certain test patients.

They also warned that women on estrogen therapy and any allergy sufferers taking antihistamines appeared to heal less quickly after the surgery.

The FDA is not bound by its advisers' recommendations but typically follows them.

Laser eye surgery can correct some vision problems by reshaping the curvature of patients' corneas, often, but not always, enough so that patients no longer need glasses. Side effects include sensitivity to bright lights and poor night vision.