Millions of people start their morning by popping in their contact lenses.

That's when Linda Polzin takes hers out.

The 51-year-old Orland Park woman wears a type of contact lens called "Paragon CRT," recently approved by the Food and Drug Administration to treat mild to moderate nearsightedness and some astigmatism.

Plenty of contact lenses bring blurry objects into crisp focus - while you wear them. But the Paragon lenses do their work while patients sleep, subtly flattening and reshaping the transparent tissue of the cornea. It's the same idea as LASIK surgery, but instead of removing tissue you're redistributing it.

Measuring about the size of an M&M, the Paragon CRT lenses are slightly larger than other rigid, gas-permeable lenses.

Most people think of rigid lenses as uncomfortable, but that doesn't appear to be a big problem with Paragon's. Only 4 percent of patients in a company-sponsored clinical trial dropped out due to discomfort.

Part of the reason the lenses are well tolerated is that they're worn while you sleep, and you don't blink while you sleep. When you wake up, you take the lenses out and go through the rest of the day being able to see without glasses or contacts - a sensation Polzin hadn't experienced in nearly 40 years.

"The first time I took them out I could see very well," said Polzin, who started wearing the Paragon CRT lenses last month. "I was thrilled. I've needed my vision corrected since I was in seventh grade. I love it."

If Polzin wants to keep up the results, she'll have to keep wearing the lenses overnight. That's because the benefits are temporary.

"It's almost like a retainer," said Charlotte Joslin, the University of Illinois at Chicago optometrist who fit Polzin's custom-made lenses. "If you stop wearing them, your condition reverses."

Joslin is one of about a dozen practitioners in the state certified to fit the Paragon lenses. She charges roughly $1,500 for the contacts, the initial fitting and six months worth of follow-up visits. Insurance generally doesn't cover the cost.

Cheryl Gilmartin of Oak Forest says her $1,500 was money well spent.

"To me it's worth it because I'm able to see so well," said Gilmartin, who wasn't a candidate for LASIK surgery because of an irregular astigmatism.

"It's just a lot nicer not having contacts in during the day, especially because I enjoy water sports, Rollerblading and things like that," Gilmartin said. "To me, this was the next best thing to LASIK surgery."

For others, LASIK simply isn't an option for any number of reasons, from potential complications to cost, which can average around $1,500 per eye.

"Patients who just can't get over that hurdle of having surgery on their eyes - this is another option for them," said Bruce Morgan, assistant professor of optometry at University of Missouri-St. Louis.

FDA gives green light

CRT, or corneal refractive therapy, isn't a new idea. A very crude version of sorts dates back to ancient China, when warriors slept with sandbags on their eyes to sharpen their vision in battle.

Almost four decades ago, eye practitioners started using certain contact lenses to put gentle pressure on the malleable cornea, changing its shape to improve vision.

As contact lens materials and designs improved over time, optometrists and ophthalmologists increasingly used a variety of rigid, gas-permeable lenses to reshape the corneas of select patients. This was done "off label," meaning the FDA hadn't approved the use of contact lenses in this way.

That changed this summer when Arizona-based Paragon Vision Sciences convinced the FDA that its contact lenses were safe and effective for corneal refractive therapy, giving Paragon the go-ahead to advertise its overnight lenses for this use.

FDA approval was based in part on clinical trials that showed 57 percent of nearsighted patients using Paragon CRT lenses had 20/20 vision or better, while 96 percent had at least 20/40, the requirement set by most states to drive a car without glasses. These results are on par with LASIK, according to the American Society of Cataract and Refractive Surgery.

It's worth noting that of the 205 people enrolled in Paragon's nine-month study, 122 finished it. The most common reason for dropping out was that volunteers weren't satisfied with their vision.

Over the nine-month study, there were three reports of so-called adverse events: a scratched eye, moderate swelling in the cornea and bacterial conjunctivitis similar to pink eye. All three problems resolved themselves without permanent damage.

"From a safety standpoint, we come out with all A's," said Paragon Vice President Jerry Legerton, one of the creators of the company's CRT lens. "The main symptom that was reported was discomfort, and that correlated very closely with what you would see with any rigid lens study, and it decreased over time."

Indeed, safety is bound to be a big selling point for CRT, said University of Missouri's Morgan, one of the clinical trial researchers.

"You're doing something similar to refractive surgery, but you have the safety level of just wearing a contact lens that can be removed," Morgan said.

Alternative to LASIK

Safety is what made Polzin opt for lenses over LASIK, surgery in which a doctor cuts a flap in the cornea and then zaps away tissue with a laser.

With the right patient and an experienced surgeon, LASIK is considered a very safe procedure. Studies show the rate of severe complications to be less than 1 percent. According to industry estimates, about 5 percent of LASIK patients face some post-operative problems, from dry eyes, glare and the appearance of halos to inflammation and impaired vision. Some of these complications are temporary and fixable, others can be permanent.

Contact lenses can cause side effects, too. Dry eyes, itchiness, inflammation - even vision-robbing infections, although those are very rare. Even so, people generally feel much safer with contacts than they do with eye surgery.

"I did consider LASIK, but I just have a fear of it," Polzin said.

Fear isn't the only thing keeping people away from LASIK.

Some patients simply are too young for the refractive surgery. You need to wait until your corrective vision prescription is stable before having LASIK, and that might take some people into their early 20s. There's no such age restriction for CRT. "We've treated people as young as 7¨," said S. Barry Eiden, an optometrist with North Suburban Vision Consultants in Deerfield. "At least 60 percent of our CRT patients are under the age of 25."

CRT lenses not only help children see, they may keep kids' vision from deteriorating as much as it normally would. That's the theory being tested in an Ohio State University study, which is looking at the potential of CRT to actually slow the progression of nearsightedness in children between the ages of 7 and 11.

One advantage LASIK has over corneal refractive therapy is that it works on more severe forms of nearsightedness and astigmatism. And unlike CRT, it can be used to treat farsightedness.

"With LASIK, the vast majority of people who wanted to have it done have had it done," Eiden said. "What's left over are a lot of people who aren't quite comfortable with the permanence and are concerned about complications that might not be reversible. The beauty of CRT is the total reversibility of it."

Yet one of the very things that makes CRT lenses appealing - their reversible, temporary effect, for example - can also be a drawback, said Dr. William Zeh, a refractive surgeon with Saint Louis University.

"This is not a permanent cure for the problem," Zeh said. "The patient has to sleep with these contacts in indefinitely. And it's not likely in the long run to be an inexpensive option because they need to replace the lenses and have ongoing eye exams."