Local optometrist patents invention

Jan. 20, 2011

By Tim Simard
Observer staff
Dr. Thomas Clark (right) fits a pair of bifocals for his wife, Anni. Clark, an optometrist with an office in Blair Park, developed a patent in 2009 for better-fitting progressive lenses and recently completed work on a prototype. (Observer photo by Tim Simard)

For years, Williston optometrist Dr. Thomas Clark ran into the same frustrations time and time again, with some patients continually encountering blurred vision with their eyeglasses despite having the correct prescription. Now, after years of research, Clark believes he has found an answer that may make the lives of millions of bifocal wearers a lot easier.

Clark, a Burlington resident, received a U.S. patent in December 2009 for an invention that he calls the Visual Access Alignment Device. The device can better measure a patient’s vision and ensure an exact prescription. For the past year, Clark has developed the invention to the point where he now says major eyewear companies are interested.

“It gives the correct answer to the question, ‘Where do I put the bifocals in a frame?’” Clark said.

Clark, who specializes in most fields of vision, has found that patients who need progressive bifocal lenses sometimes encounter difficulties seeing clearly when new glasses arrive. Progressive bifocals allow near-sighted patients to have better vision, but the lenses must be placed precisely for the patient to see clearly.

“I was struggling for six or seven years trying to figure out why these accurate measurements were not accurate,” Clark said. “It got to the point where I realized it wasn’t me making a mistake.”

Using the traditional method of measuring one’s vision did not work for all patients, Clark learned. He believed there had to be a way to correctly calculate vision the first time and avoid the time-consuming and costly eyewear revisions.

Clark decided to take matters into his own hands. He learned that most devices for measuring progressive lenses only gauge the pupillary axis — the line where a patient’s pupil meets an object — then focuses on it for clarity. He found that in some instances, the best clarity came when he measured a patient’s visual axis, or direct line of sight.

The difference between the pupillary axis and the visual axis is small for most bifocal wearers, but others have a much larger separation between the two lines of vision, Clark said.

“That can make all the difference,” Clark said.

Entering the world of inventions and patents proved challenging, Clark said; he relied on several experts to help him work through the complicated process. Receiving the patent turned out to be only the beginning. With patent in hand, he spent much of 2010 creating a workable device.

By tinkering with vision equipment, Clark transformed a traditional bifocal measuring device into one that measures visual axis. In a typical setting, a patient will look through a device operated by an optometrist and let the doctor know when the image in the mechanism becomes clear. In Clark’s version, a patient holds the measuring device and looks through it like a pair of binoculars. The patient then adjusts the settings to make the image sharp.

Clark said approximately 10 percent of progressive bifocal wearers encounter difficulties in getting a correct fit that doesn’t equate to traditional measurements. But Clark believes that small population could translate into significant savings for vision companies that spend millions of dollars annually refitting progressive lenses. He said the invention might also help people who have been turned off by the lenses because of poor experiences.

Clark said he has received interest from an international vision company that’s reviewing his patent and invention. He said the company may decide to redo the look of the invention, but the conceptual properties would remain his idea. Clark doesn’t know when he will hear back from the company or if it will want to manufacture the product.

“This is all new to me, so we’ll see,” Clark said.

Clark is also looking for more people to try out his alignment device for a study to back up his findings. He has already tested his patients, but wants additional subjects to help pinpoint more accurate results. Anyone interested in participating in the study can call Clark at his office in Blair Park at 862-1947.