When Terri Rhinehart turned 40, everything started to get blurry. Rhinehart, who owns an engineering and software company in Portland, Oregon, suddenly couldn’t read menus, books in low light, or the small numbers she’d need to register when doing accounting for her business. She got reading glasses, but she had to keep asking for a stronger prescription when her eyesight continued to worsen.

“I had to bring out a magnifying glass for some things,” 50-year-old Rhinehart told FoxNews.com. “I would feel dizzy; I just didn’t feel right.” She also used glasses to see at a distance until getting LASIK surgery, which is only used to correct nearsightedness.

Rhinehart was suffering from presbyopia, or age-related near vision loss, which affects the entire world population and, until now in the United States, could be remedied only with reading glasses or surgeries that would compromise either the contrast or richness of color people perceive, or would affect distance vision. But now, Americans have another option to help them see up close that does not affect other aspects of vision: a small, removable inlay that manipulates the amount of light entering the eye.

“Every day it’s getting better and better,” said Rhinehart, who got the KAMRA inlay in early September, following the Food and Drug Administration’s (FDA) approval of the procedure in April. “I’m only a week and a day out, and I can already read small print, I can read on my phone, I can read menus when I go to restaurants.”

While small aperture optic procedures for presbyopia have been performed in Europe for the past 25 years, Rhinehart is one of 500 Americans who has undergone the procedure since the FDA approved it in the U.S. Over 25,000 people worldwide have undergone similar procedures for presbyopia.

The KAMRA inlay— a mini ring that measures about the size of the pupil, weighs less than a grain of salt and is one-tenth the thickness of a human hair— works like a camera lens with an increased F stop. That is, the small space in the inlay allows only focused light to enter the eye, thus making perceived objects look clearer. 

“Because we’re only allowing light to come into the small opening of that mini ring, then everything from distance to near, and everything in between, is focused,” Dr. Tom Tooma, medical director and founder of NVISION Eye Centers in Newport Beach, Calif., and one of 40 U.S. surgeons authorized to perform the procedure, told FoxNews.com. Tooma noted the procedure doesn’t turn back the clock completely, but it restores a patient’s vision to that of someone in his or her 30s.

Before inputting a KAMRA inlay, Tooma does a 15-minute consultation with each patient. Individuals who are age 45 and older, and those who haven’t undergone cataract surgery, are eligible. The inlay is one size fits all. Prior to undergoing the procedure, Tooma recommends patients take an anti-anxiety medication like Xanax. He then uses a femtosecond laser to create a pocket with a smooth bed in the cornea, where he inserts the inlay.

“If the cornea was a 500-page book, the inlay goes at about page 200,” said Tooma, who was also a study author for clinical trials of the KAMRA inlay in the U.S., which began in the late 2000s.

From start to finish, the procedure takes less than 10 minutes and is painless. He usually recommends patients take the next day off work to adjust.

Fernie Molina, the first patient to get the KAMRA inlay at Tooma’s clinic, had undergone LASIK surgery to correct nearsightedness, but he got tired of trying to remember his reading glasses while working as a transmission technician in Palmdale, Calif., to correct his farsightedness. When he heard the FDA was slated to approve the KAMRA inlay, he signed up for the procedure right away.

“No pain at all— you just come in, and it’s nothing,” Molina, 52, told FoxNews.com of the KAMRA inlay, which he got about three months ago. “My life is great now: I can read, I can see up close, I don’t even wear my [reading] glasses anymore.”

Near vision usually doesn’t immediately improve with the KAMRA inlay, as with successful LASIK surgeries, but it does so gradually over two to four weeks following placement.

A common side effect of the procedure is dry eyes, and about 6 percent of patients will still need glasses for reading in low light after getting the procedure. Molina and Rhinehart said they’re taking eye drops two to three times a day for dry eyes.

An estimated 1 to 2 percent of patients have the procedure reversed due to lack of success or discomfort, said Christopher J. Quinn, O.D., vice president of the American Optometrist Association, and president of Omni Eye Services, which has offices in New Jersey and New York.

“Anytime you do a surgery on the eye, there’s risk,” Quinn, who has referred patients to ophthalmologists for the procedure, but was not involved in the research or development of the KAMRA inlay, told FoxNews.com. “There can be inflammation or infection, and that’s part and parcel with almost any technology. Of course, wearing a contact lens also carries a risk of develop an infection.”

The beauty with the KAMRA inlay is that “if something does happen, it can be removed and the patient is right back to where they were preoperatively,” Nicholas Tarantino, O.D., chief clinical and regulatory officer of AcuFocus, the Irvine, Calif.-based company that manufactures the KAMRA inlay, told FoxNews.com.

Being able to reverse the procedure is another feature that makes the KAMRA inlay different from LASIK surgery, which involves permanent tissue removal to reshape the cornea, improving how the eye focuses light rays into its retina. Inputting the KAMRA inlay does not require remolding the cornea, but rather it places the removable inlay within a pocket that’s sealed by a 50-micron epithelium from the outside that can be easily reopened.

The KAMRA inlay procedure isn’t covered by most insurance plans, and ophthalmologists typically charge about $4,000 to $5,000 for the inlay, depending on the region of the U.S., Tarantino said.

An estimated 122 million Americans and 2.1 billion people worldwide will suffer from presbyopia within the next few years.

“It affects everybody— it’s an aging thing,” Tooma said. “It’s not a disease that happens to some people and not others. But 100 percent of the population, sometime in their 40s, will need reading glasses.”

“There’s nothing as good as what our creator has done,” Tooma added, “[but] this comes close— we try to fool Mother Nature … same thing as if you have an artificial knee and hip. A face-lift is never as good as 30-year-old’s face. It is a procedure that works beautifully and we’re ecstatic with it, but it’s not as good as a 20-year-old eye, but it does reverse the clock.”