(FORTUNE Magazine) – Saturday mornings in Dr. Barrie Soloway's ophthalmology clinic have the feel of an old-time revival meeting. Maybe not when you first walk into the bright white, marble-floored waiting room: There, patients who have had laser eye surgery the day before sit quietly in rows of chairs against the walls, with little clear-plastic shields awkwardly taped over their eyes. But follow them, one by one, back into the exam rooms where Soloway removes the shields, and you hear exclamations straight from a faith healer's tent: "It's a miracle!" Or "You've changed my life!" Or just plain "I can see!"

Eyeglasses, which people have relied on for eight centuries, are finally on their way to obsolescence. That's the contention of Soloway and some 3,000 ophthalmologists like him around the country who do laser vision correction. Whether you're myopic (nearsighted), hyperopic (farsighted), or astigmatic (your corneas are warped in some way that impairs your sight), getting your eyes reshaped by a laser can bring the world into focus. There's even a surgical solution in the works for presbyopia, or aging-eye syndrome--the affliction that drives nearly all middle-aged people into reading glasses. "Bad vision no longer has to be a disability," says Soloway. "It can be fixed, permanently."

The laser treatments have drawbacks--they'll cost you $2,200 per eye, and you must be willing to risk side effects stemming in part from the fact that the technology isn't perfected. But according to analyst Irving Arons of Spectrum Consulting in Peabody, Mass., laser surgery is already an $840 million business that in 1998 treated 250,000 Americans. "Back in the '70s, we debated whether anybody should be having surgery just because they're wearing glasses," says Dr. Daniel Durrie, director of the Hunkeler Eye Centers, a chain of eye clinics in Kansas City, Chicago, and St. Louis. "There may come a time when people will look back and wonder why we ever hung something on our ears and nose to make our eyes see better."

Surely by now someone has told you how laser surgery has let them throw away the Coke-bottle-thick glasses they've worn since age 9. Vincent Cazzetti, a managing director at Bear Stearns & Co., heard enough to know he wanted to entrust his myopic brown eyes to Soloway's laser. On a Monday afternoon in August at the New York Eye & Ear Infirmary, he lay on a padded table attached to a hulking four-foot-high beige cube that is the half-million-dollar Visx Star 2 laser, his tanned hands resting on his chest. Soloway, talking slowly and steadily as he worked, cleaned Cazzetti's left eye, daubed it with anesthetic, taped his lashes to his face, and placed a speculum to hold open the lids (picture Malcolm McDowell's brainwashing in A Clockwork Orange). "I want you to think how wonderful it's going to be to be out on the golf course without your glasses," Soloway said. "Just keep looking straight at that flashing red light above you."

Soloway peered through a microscope over Cazzetti's head and wielded his microkeratome--a gas-powered stainless-steel instrument that, like a tiny carpenter's plane, carves a thin flap in the top of the cornea. The knife buzzed like a dentist's drill for about ten seconds; Soloway peeled back the flap like Saran Wrap. Then, working a joystick, he aimed the cube's laser at the surface beneath.

A rapid-fire clicking was audible as pulses of ultraviolet light bombarded Cazzetti's cornea. Unlike the red lasers factories use to blast holes in steel, the beam of this so-called excimer laser is low-temperature and invisible. It vaporized the collagen molecules of Cazzetti's cornea until, after 12 seconds, it had been pared down in the center by about 30 microns (less than half a hair's width). Soloway lifted his foot from the control pedal and brushed the filmy flap of cornea back down. "We're halfway done," he announced, and Cazzetti's index fingers twitched up and down. He lay quietly for a few minutes--for the flap to adhere--and then Soloway covered the eye and started on the other.

When the procedure ended--the whole thing took 15 minutes--Cazzetti sat up, and Soloway asked him to look at the clock. "Son of a gun," Cazzetti smiled. "It's 25 to six!"

After 45 years, Cazzetti can get rid of his glasses--all 12 pairs of them. No more straining to see the baseball when his grandson pitches. His vision has been corrected to 20/20 in his right eye and 20/40 in his left. (Soloway left a little nearsightedness in the left eye so Cazzetti could use it for reading.) A very good result. Still, Cazzetti can expect to see some glare around things at night, when his pupils open enough to take in light from the outer edges of his corneas. He's likely be more sensitive to bright light, at least for the first few months. And he'll have to see whether he can adapt to using his right eye for distance and his left for reading.

Would Cazzetti have been wiser to wait for the technology to improve? Soloway is highly experienced--he has treated more than 1,000 patients--and probably lasered the corneas as smoothly as possible. Still, if Cazzetti had held off just one month, Soloway could have done the surgery with a new laser that incorporates state-of-the-art eye-tracking technology and uses a much narrower beam. If Cazzetti had waited a year or two, he might have chosen to forgo laser surgery altogether and instead have had lenses implanted in his eyes to give him perfect vision. If he'd waited, say, three years or more, another laser technology might have given him better-than-perfect vision--as good as 20/10.

Cazzetti is what's known as an "early adopter"--he is among the first wave of customers putting their eyes under the laser, those who think it works well enough at this point, so why wait? Since 1995, when the surgery was approved in the U.S., the number of takers has doubled each year, opening a huge market for ophthalmologists, laser makers, eye-clinic managers, and investors. In 1999 it may reach a half million, making laser eye repair the most frequently performed surgery in all of medicine. Almost all the procedures are LASIK (laser-assisted in situ keratomileusis), the flap-and-zap surgery Cazzetti had.

Given how fast the market is growing, it may be only a few years before the less adventurous among us go under the laser. Even then, glasses will take decades to vanish. Some 162 million people in the U.S.--an eye-popping (sorry) 60% of the population--wear glasses or contacts; the nearsighted alone number 70 million.

So the LASIK phenomenon is only the beginning. Already the FDA has approved an alternative way to fix nearsightedness--by planting tiny crescent-shaped pieces of plastic, called Intacs, in the periphery of the cornea. In the works are other nonlaser treatments, including implantable lenses. For farsightedness, two technologies are being developed--hot lasers and radio-frequency energy. They shrink tissue on the periphery of the cornea, correcting its curvature. They're both at least a year off--probably more.

Laser correction, meanwhile, is being significantly refined. Borrowing optical technologies developed for the Reagan-era Strategic Defensive Initiative to track incoming enemy warheads, engineers at Autonomous Technologies in Florida are creating ever more precise and effective lasers. Along with new vision-measuring techniques, they may give people "supernormal" 20/10 vision (also known as Ted Williams eyesight). "The Holy Grail is not only to correct your nearsightedness but also to get you to see better than you could even with glasses," says Minneapolis ophthalmologist Richard Lindstrom, who runs one of the busiest refractive surgery practices in the country. Some doctors imagine they may ultimately use surgery to make hawk eyes of people whose vision is already adequate.

Early adopters like Cazzetti typically are active people for whom glasses and contacts are a particular nuisance. (Quarterback Troy Aikman, baseball star Wade Boggs, tennis player Michael Medvedev, and golfer Fred Funk have had the surgery.) They are also largely the kind who like to be first with things, who rush out to get a Palm VII or the latest gas grill. And they're comfortable with a certain amount of risk. (Mark McGwire has said he considers the risk of laser surgery too great.)

Complications happen in some 5% of patients--but in fewer than 1% of those whose surgeons are experienced. The side effects can be more than a little annoying. Many patients, especially those who start out severely nearsighted, end up still needing glasses--though perhaps not such thick ones as before--for driving at night or watching movies. Sometimes when a patient's vision isn't fully corrected, the doctor has to do an "enhancement"--reopening the flap and lasering more--six months later.

Infections can develop. If the lasering isn't perfectly smooth, you can get haze in the cornea that may make it impossible to see 20/20 even with glasses. Worse, something may go wrong as the flap is made. The doctor may clumsily slice a hole in the center (a "buttonhole") or cut the layer of tissue totally off, leaving no hinge. Sometimes a flap heals improperly, so you end up with wrinkles around the edges. These problems can make it impossible to complete the surgery or can cause fuzzy vision.

If you use reading glasses, laser surgery can't help. It does nothing to prevent the weakening of the eye's ability to focus close up when a person ages beyond about 45. Once that occurs, if your distance vision is still good, you need reading glasses; if you're nearsighted, you need bifocals. Some laser surgeons attempt to relieve the problem by leaving a little nearsightedness in one eye, as Soloway did with Cazzetti. Known as monovision, this fix doesn't always work. About 20% of people are unable to adapt to reading with one eye; what's more, monovision limits depth perception. (To cite the most jarring example: A few years ago a Delta Air Lines pilot with monovision crash-landed at LaGuardia Airport during bad weather. Investigators blamed the crash, which injured 58 passengers, on the pilot's diminished depth perception.)

Because of these limitations, ophthalmologists find they must be careful about what they promise. "When people come to me and say, 'I hear the laser is totally safe and I can throw away my glasses,' their expectations are too high," says Dr. Walter Stark, director of corneal surgery at Johns Hopkins Medical Center in Baltimore. "The patient has to realize there's a small risk of complications, and it can happen to them."

Some doctors say all expectations for LASIK are too high, because it's a mistake ever to alter the center of the cornea. "Eye doctors, when they're little boys, are taught to stay away from the center of the cornea, the visual axis," says New York ophthalmologist G.A. Hecker. Like many critics, he warns that the procedure hasn't been around long enough for anyone to know its long-term effects. "If someone in their 20s has the surgery, we're talking about people who are going to live several more decades, and the cornea gets weaker as you get older."

LASIK practitioners agree that if the cornea gets too thin it may balloon out like a weak spot on a bicycle tire--but say this won't happen if you avoid cutting too deeply. The average cornea is about 550 microns thick, and as long as you leave more than 200 microns of thickness, the eye will be fine.

At this point, few patients are complaining. San Francisco lawyer Caren Jenkins, who had LASIK four months ago, is typical. She experienced a little glare at first, but it has gone away. Her only real problem was an inability to adjust to monovision; after three weeks she gave up and returned to her doctor, Stephen McLeod, at the UCSF Vision Correction Center, to have her reading eye re-lasered to make it 20/15 like the other one. More important, she went from being barely able to make out her hand in front of her face to having better-than-perfect vision. "Absolutely, without question, I'd do it again," she tells colleagues at her firm, Graham & James, three of whom already have seen McLeod about the surgery.

It's this kind of word of mouth--what promoters call the "wow factor"--that's made LASIK the first kind of laser eye surgery to really take off. An earlier, simpler procedure known as PRK involved taking tissue off the surface of the cornea. Still performed by some ophthalmologists, it was just as effective for most patients. But because it cut into the cornea's surface, the eyes took longer to heal, and many people felt pain, especially during the first few days after surgery.

"The patient's friends would call the first night, and he'd tell them it hurt," says Lindstrom of Minneapolis. "LASIK, on the other hand, is almost painless. Friends who call that night call me the next day to make an appointment." Doctors say that the average LASIK patient refers an average of five friends in the course of a year, and that 75% of their new patients are referrals.

The wow factor is also attracting investors. Companies involved in LASIK--including both laser makers and chains of laser-surgery centers--have lately seen their share prices soar as if they had a dot.com in their names. In the past year, most laser surgery stocks have more than tripled.

Visx, which makes the laser used in 70% or more of all LASIK procedures in the U.S., is leading the charge. The Santa Clara, Calif., company earned $73 million on $194 million in sales in its most recent four quarters; in the past three years it has grown so strongly that it ranks No. 29 on FORTUNE's list of America's 100 fastest-growing companies. Virtually all the lasers at eye-surgery chains are Visx units.

Summit Technologies, which earned $39 million on $99 million in sales in the past four quarters, is No. 2 in the market. Although it pioneered the use of excimer lasers in eye surgery, the Waltham, Mass., company lost its early lead by focusing too much on opening its own clinics rather than improving its laser. Now--after selling all its clinics--Summit is playing catch-up. Its Apex Plus laser is close to gaining FDA approval to correct as broad a range of vision problems as Visx's device (virtually any level of nearsightedness, with or without astigmatism, plus farsightedness without astigmatism). And last year Summit acquired Autonomous, the Florida startup that applies Star Wars technology to laser surgery. Aiming to leapfrog Visx, it plans to install at least 50 of its new LADARvision lasers in U.S. doctors' offices this year. Two other contenders are also seeking FDA approval to launch lasers: Bausch & Lomb, the $2.4-billion- a-year eye-care giant, and LaserSight, a Winter Park, Fla., startup.

Visx and Summit dominate in part because they jointly control key patents on the use of excimer lasers in eye surgery. Each time a doctor lasers an eye, the companies get a $250 royalty. (In Canada, where the fees don't apply, LASIK costs under $2,000 per eye.) The companies defend the patents ferociously: When Nidek, a Japanese laser maker, got FDA approval for treating nearsightedness last December, they promptly sued it for refusing to pay royalties. "They're just trying to prevent us from entering the market," complains David Yeh, director of sales for Nidek U.S.A.

Visx has been fierce: It even sued, for triple damages, doctors who use the Nidek laser. Dr. Keith Thompson, an Emory University ophthalmologist who is a Nidek consultant, charges that these actions keep doctors from using the laser of their choice. The Nidek device can perform LASIK more smoothly than a Visx machine, he argues, because it has a "slit scanning" beam that operates in a kind of sanding motion that smoothes out imperfections. "Visx is this 800-pound gorilla suing doctors to coerce them to use a product that may not be in their patients' best interests," says Thompson. Visx CEO Mark Logan rejects that argument. "We took this technology from nothing and turned it into an industry and handed it over to the doctors," he says, "and in the process we spent about $100 million. Now we want to make some of that money back."

Nearly half the laser eye surgeries in the U.S. are performed by publicly held chains. The Laser Center, a $147-million-a-year company in Mississauga, Ontario, is North America's largest, with 58 lasers in 25 states and provinces. In an effort to keep up its 100% annual growth rate, it is looking to make laser surgery more affordable. Recently TLC launched a program to encourage employers to cover some of the cost. (Employee health plans typically don't reimburse for laser eye surgery because it's an elective procedure.) Under its program, TLC lets companies offer employees a $200 discount on laser surgery at its centers. So far, some 40 businesses, including Southern California Edison, Ernst & Young, and Office Depot, have signed up. TLC also has an agreement with Vision Services Plan, a managed vision-care provider, to offer a $600 discount on laser surgery for VSP's 25 million members, and an agreement with Kaiser Permanente, the huge California HMO, to provide laser surgery to Kaiser's 18 million members at a $200 discount.

Laser Vision Centers, the No. 2 chain, has a different strategy for bringing eye surgery to the masses: mobile lasers. The $52-million-a-year St. Louis company has a patented cart that makes it possible to transport a Visx laser to ophthalmologists' offices, set it up for surgery for a day or two, and move on. Laser and microkeratome technicians are part of the traveling package. The company provides lasers for 363 doctors at 110 locations--mainly in Florida, Texas, California, Minnesota, and the Dakotas--and is expanding fast.

The next advance in laser surgery is likely to be the laser by Autonomous, the company recently acquired by Summit. Autonomous founder Randy Frey realized in the early '80s that a radar he had developed for aiming lasers to intercept enemy nukes could also solve one of the big problems in laser surgery--the eye's tendency to move while under the beam.

At present, doctors stabilize the eye merely by asking the patient to stare at a blinking red light. But, says Frey, aiming a laser at the eye is "is a very precise thing. I couldn't imagine that you could make optics for the human eye while the eye was moving." The eye, he explains, makes barely perceptible, involuntary movements about five times a second. This "saccadic" motion can make it difficult to get a perfectly smooth correction. "The doctor can compensate for the big, noticeable movements," Frey says, "but not the little ones." Obviously, given LASIK's track record, most patients get good results anyway. But saccadic eye movements may be why some LASIK patients end up with haziness in their corneas or less than perfect vision.

Frey's machine uses radar to check the position of the eye 4,000 times a second. He's coupled this with an excimer laser whose beam is less than one millimeter in diameter, vs. six millimeters for the standard beam. Guided by the tracker, this laser ablates the cornea in a pattern of small overlapping dots.

This summer, New York's Dr. Soloway became the first in the Northeast to get one of Frey's lasers. He says many patients have been waiting for it because they worry about holding their eyes steady during surgery. "I tell them, 'With this laser, as long as you're lying on the table, it will find you,'" Soloway says.

Laser tracking is just the start. The laser companies as well as many university scientists are at work on what everyone assumes will be the next technological leap: the ability to map the patient's eye so exactly that you can guarantee 20/10 vision. "We say we want to provide our patients with 20/10 vision by 2010. Hopefully, though, it will happen by 2005," says Hakan Edstrom, president of Bausch & Lomb Surgical. "We'll be 20/10 by 2000," promises Thompson at Emory.

What they're all working on is so-called wavefront technology, an adaptation of the optics that telescopes use to compensate for atmospheric distortions. These instruments would measure every possible aspect of how the eye refracts light, including the topography of the cornea, the lens (the crystalline structure behind the iris), and the retina (the back inside surface of the eye), as well as the eye's overall shape. Once you have these data, you can create a pattern for sculpting the cornea. Presto, the patient can see five times as many stars in the night sky or identify a butterfly on a tree from 20 yards away.

Thompson and Frey are among those who believe that once such procedures are perfected, doctors will be able to correct the one common form of vision impairment that today's LASIK can't help--presbyopia, the reading problems that come with age. Eventually, they say, the sculpting will be so precise that it will be possible to carve the cornea into a smooth, bifocal lens, so that the lowest portion could be used for reading and the rest for distance vision.

That is not the only technology in the works for treating presbyopia. Ronald Schachar, founder of Presby Corp. in Dallas, has a device to help muscles work better in aging eyes. Presbyopia occurs because the lens never stops growing--it continually adds layers, like an onion. By the time a person hits middle age, the lens is so large that the muscles attached to it have too little room to work properly. So Schachar has created little plastic rods called "scleric expansion devices" that can be surgically set at four locations around the circumference of the eye, just under the surface of the white part (the sclera). The rods are placed through little "belt loops" cut into the sclera. Because they're slightly arched, their backs press outward, expanding the eye and giving the muscles more room to work.

So far, the devices have been tried on only about 40 people, but Schachar says they seem to work well. He estimates it will take three to four years to complete full-fledged clinical trials. Investigators will be looking to see whether the correction lasts, and whether it does anything to weaken or damage the eye. Trials begin this year at six locations across the U.S.