Vision correction options increase for presbyopic patients

Eye wear systems developed by two companies may offer presbyopic patients the option of an accommodating spectacle lens.

TruFocals technology

Adrian Koppes, chief executive officer and co-founder of TruFocals, has been working with Stephen Kurtin, PhD, to develop eyeglasses that have a prescription rigid lens in the front and a flexible membrane lens in the back, hinged together, so that on one side the lens is fixed and on the other side it can be moved back and forth. Between the two lenses is a silicone oil-based optical fluid, Mr. Koppes said in an interview.

When the wearer slides a knob located on the bridge of the eyeglasses, the upper part of the lens is squeezed and the seal between the two lenses is compressed, forcing the optical fluid to exert throughout the membrane and creating a reading add.

The TruFocals lens can be adjusted from 0 to 2.75 D of add to achieve optimal vision at any distance, Mr. Koppes said, which makes it feel as if there are multiple pairs of single-vision lenses inside one pair of TruFocals, he said.

“The front rigid lens is your distance prescription and is available in +4 D to -8 D, in 0.25-D increments, with astigmatic correction of up to 3 D, also in 0.25-D increments,” he told Primary Care Optometry News. “We can even build in prism. In addition, we build in the adjustable add range, which allows up to 2.75 D of add.”

According to information provided by TruFocals, when wearing the eyeglasses, closer objects are brought into focus by moving the slider to the right, which displaces the optical fluid and forces the flexible lens to bulge outward. This incremental bulging reduces the membrane’s radius of curvature, thereby increasing the optical power of the focusing unit. When set to see at a distance, or the minimum optical add, the surface of the membrane is flat.

Mr. Koppes noted that because the technology is dependent upon a circular lens to function properly, TruFocals are only available in one lens and frame shape, though the stainless steel frames can be painted, depending on volume ordered.

Because of the mechanical function of the TruFocals lens, optometrists need to be cognizant of how adjusting the frames to fit a patient may influence the technology.

“Optometrists have to register on our Web site, and then we will discuss the benefits of us working together,” Mr. Koppes said. “The glasses will have to be fitted and adjusted by an optometrist. We have very flexible nose pads, wires and temples. All optometrists have the equipment to adjust the glasses; they just have to make sure that they don’t interfere with the actuating mechanism.

Mr. Koppes added that presbyopic LASIK patients are also benefiting from this new technology. “After LASIK, each eye is slightly different, and normal readers do not give them good function,” he said. “The TruFocals allow you to compensate for the difference between each eye with a distance vision correction lens, which can be adjusted to help you see clearer.”

Mr. Koppes added that TruFocals have been commercially available since June.

PixelOptics technology

Electronic focusing eye wear was developed by a team of scientists and engineers at PixelOptics to improve vision performance and comfort for individuals who wear progressive-addition lenses (PALS) and those who could not get used to PALS. The lenses allow the eye wear to focus on text within the reading zone by increasing the image size. When switched on the wearer will experience less distortion in the periphery. The eye wear allows for vision correction at a far distance, near and intermediate.

Ronald D. Blum, OD, president and CEO of PixelOptics, told PCON that the composite lens product contains a buried pixilated optic that is activated by switching the liquid crystal index of refraction, which allows the diffractive optic to turn the near power on or off. When set to “automatic,” the glasses automatically focus without patient assistance, based on the tilt of the eyeglasses.

“We use a sophisticated tilt switch called a microaccelerometer,” Dr. Blum said. “If the patient is looking at far, the eyeglasses know that they are looking into the distance. If the patient looks down, the tilt switch senses that the eyes are tilting, and it automatically switches the lens to a reading prescription.”

According to Dr. Blum, three modes of operation are available: automatic, manual on and manual off, which allow the user to turn the “near reading” power off when desired. Patients must touch the frame near the temple for 2 seconds, which will activate an electrical signal within the eye wear to switch it to automatic. Swiping a finger across the temple will freeze the eye wear in a reading prescription, while a swipe in the opposite direction will turn it off, he said.

“For people who are looking at something straight ahead and need the reading prescription, they can freeze the glasses so they focus 16 to 18 inches from the face. Artists and electricians might find this particularly useful,” Dr. Blum said.

The eye wear operates by using a rechargeable hidden battery situated within the temple of the frame.

“The battery should last for over 2 years, but if it goes bad or the glasses malfunction electronically, the consumer can see their eye doctor and have the temple, where the module is housed, switched out,” Dr. Blum said.

To ensure proper function, the eyeglasses should be charged every night, but at least once every 3 days.

William Spies, chief operating officer of PixelOptics, said that accessibility and allowing for different shapes, colors and styles of the product was crucial in the development plans for the electronic focusing eye wear.

“We’ve worked hard to develop this product so that it fits within existing channels of distribution,” he told PCON. “Eye care professionals will get this product through the laboratories.”

PixelOptics plans to launch the eye wear in late 2010 after conducting more expanded clinical testing.

For more information:

• Adrian Koppes is CEO and co-founder of TruFocals. He can be reached at 7065-2 Hayvenhurst Ave., Van Nuys, CA 91406; (818) 785-7778; e-mail: akoppes@trufocals.com; Web site: www.trufocals.com.
• Ronald D. Blum, OD, is CEO and president of PixelOptics and can be reached at 5241 Valleypark Drive, Roanoke, VA 24019; (877) 725-3447; (540) 777-6110; fax: (540) 777-6555; e-mail: rblum@pixeloptics.com; Web site: www.pixeloptics.com.
• William Spies, chief operating officer of PixelOptics, can be reached at e-mail: wspies@pixeloptics.com.