Laser surgery that blasts away microscopic bits of the cornea could someday replace glasses and contact lenses, eye experts say.

The surgery to reshape the cornea - the outer part of the eye that acts as a lens - has been tested on about 300 patients in the United States and about 1,800 worldwide, doctors presenting the findings said Wednesday at an American Academy of Ophthalmology meeting.The results of the tests have been promising but there are still several problems, such as a hazy film that often develops in the cornea, the doctors said.

"I wouldn't have it done on myself, and I tell my patients that. I'm afraid of being the one-in-1,000 complication," said Dr. George Waring at the meeting.

Doctors also have noticed a thickening of certain eye tissue, and there is also little data available on how long the effect of the surgery lasts.

The procedure must be approved by the Food and Drug Administration before being made widely available.

The cost for the average patient is unclear but could be about $2,000, said Dr. Manus Kraff, head of the American Society for Plastic and Reconstructive Surgery.

The procedure is performed with an excimer laser, a highly precise device capable of reshaping the cornea a millionth of an inch with each pulse of energy.

"Really what we're doing is mimicking what the front surface of the contact lens does by reshaping the cornea," said Dr. Francis L'Esperance.

In about two-thirds of the patients, a "haze" develops after surgery. Only a few patients report noticing the haze, and even then they usually consider it an improvement over their ability to see before the surgery, the doctors said.