Building a Platform for VFLs
The hot market-growth category of Variable Focus Lenses can answer patient needs for clear intermediate-to-near focus viewing for the computer, office, and other work and leisure tasks.
by Karlen McLean, ABOC, NCLC

The office is a prime location for using variable focus lenses. Here are views with and without VFLs. Shown: Carl Zeiss Optical Business lenses

In today's business climate, where practices nationwide are looking for new ways to gain and retain patients, variable focus lenses offer a way to involve the entire office in the patient care of a growing demographic: Those who specifically need clear, comfortable vision up close and at an intermediate distance.

Computers are a way of life. Work activities center on top of a desk, and leisure activities including hobbies more often focus on near to intermediate viewing tasks. The time is right for variable focus lenses (VFLs).

However, some doctors and dispensers remain reluctant to use anything other than single vision lenses for computer and task- specific use, or resort to general purpose progressive addition lenses (PALs) to provide visual solutions.

"Dispensers can get locked into using specific products and stay at that comfort level, especially with PAL products where they will only dispense a small segment of what's available," says Dave Edwards, manager of South Florida Vision Centers/ Professional Vision Care, in Fort Lauderdale, Fla., and Houston.

According to Edwards, success with variable focus lenses, or with any lens design, "is about doctors and dispensers taking the time to learn about new products that can help their patients and becoming proficient in presenting, measuring, fitting, and dispensing them.

"It's also about knowing your demographics and staying current with them in order to supply the best service to your patients," Edwards adds.

For example, the dispensary recently hired two Spanish-speaking employees--one at the front desk and one optician. "I've seen our numbers go up as the local Spanish population, which has grown in the last two years, has responded by bringing in friends, family, and neighbors who remain loyal to our practice."

Here's how several eyecare professionals have quickly made VFLs part of their business model by taking advantage of the opportunity that VFLs offer to fulfill their patients' demographic needs.

	Viewing data on the screen can be made easier with the use of variable focus lenses. Shown above: SOLA's Access lenses

COMPUTER LENSES

According to recent independent research, more than half of America's workforce spends their workday in front of a computer. Figures show that nine out of 10 workers experience some form of Computer Vision Syndrome (CVS). Symptoms include tired, sore eyes; blurry distance vision and/or double vision after working at the computer; headaches and neck or shoulder pain when working at the computer; color fringes around objects; and squinting when looking at the screen.

The way eyes view a computer image is different than reading print on a page. Pixel images on a computer screen have poor edge definition, which can cause repetitive focusing effort for eye muscles.

A study published in the January 2004 AOA Journal, conducted at the University of Alabama at Birmingham School of Optometry, revealed that a miscorrection of as little as .5 diopters (two clicks of the phoropter) can affect worker productivity by around nine percent and accuracy by 38 percent.

Kent Daum, OD, PhD, associate professor in the university's department of optometry and the study's chief investigator, comments: "We found that even when CVS symptoms were not reported and the computer screen was seen clearly, there were differences in productivity and accuracy over time. While ergonomic considerations are important in terms of productivity and relief of CVS symptoms, they won't in themselves fix a visual problem. This can only be done with the right computer lens prescription."

The study concludes that the correct Rx, coupled with variable focus lenses, is the best solution for more than 90 percent of computer users.

While this research reflects work-related usage, it doesn't account for casual computer use at home. The study examined subjects ranging from 19 to 30 years old--leaving out kids, teens, emerging and long-time presbyopes, and senior citizens, who are all increasingly using the Internet.

Mark Cohn, OD, in private practice in Bellevue, Wash., was open to the concept of computer vision syndrome and its correction early on. Cohn's office is located about eight blocks from Microsoft headquarters and close to several Microsoft spin-off companies, so he and his staff see "computer eyes" daily.

"I talk about computer vision in the exam room. But the process really begins before the patient is in my chair," Cohn says. "We have computer vision materials on display in the waiting area, in the exam room, and in the dispensing area. During pre-testing, our technicians ask patients questions about their work habits, and add any pertinent information to the chart so I can discuss it with the patient during the exam."

Eyewear for computer and deskwork are recommended, he tells patients how specialized eyewear for this purpose will make their eyes more comfortable and their lives easier.

Children are a growing variable focus lens market segment. Shown, PRIO's Computer Lens

He also cautions, "Don't drive with these. They are not for distance vision. These glasses live at your desk; keep them there."

VFLs are preferred for office situations over other choices because Cohn and his staff find they provide the most stable mid-range vision.

The practice has a 90 percent acceptance rate with VFLs. The other 10 percent either have a larger than 21" computer screen ("if the screen is too wide, VFLs are often unsuccessful," he says) or are using more than one computer--often two to three computers--at one time, which caused too much head movement for the lens to work well.

Occasionally, non-presbyopes or those who have never worn eyewear prior to their VFL eyewear add to the practice's non-acceptance mix.

The office typically bundles variable focus lenses with anti-reflective, UV, scratch protection, and a light tint for a complete "visual comfort" package.

GOOD FOR EVERYONE

"All our staff uses variable focus lenses, and so do I," says Cary Herzberg, an OD in private practice in Aurora, Ill. "Being able to talk about and demonstrate variable focus lenses first-hand carries a lot of credibility."

The practice uses lots of VFL materials to help add to its verbal message about near-to-midrange focus lenses with patients. Specialized computer programs are also used to demonstrate the effects of CVS on the eyes and how VFLs can help correct the condition.

"We take an extensive patient history, asking specifically about vocational needs. Following my examination, I will recommend the lenses to patients who would benefit from them, and write a prescription for variable focus lenses," Herzberg says. "I specify exactly which design and brand. Then I hand off the Rx to the optician and, with the patient listening in, briefly explain what my recommendation is to the optician."

As a pediatric specialist--more than 60 percent of his practice is pediatrics--Herzberg and his staff consistently talk with kids about what they do.

	Hobbies, office work, and tinkering around the house are potential applications for VFLs. Shown, Rodenstock's Comolit Office lenses

"Most kids are on the computer over two hours a day," Herzberg notes. "You have to evaluate every patient and every situation, no matter their age."

VFLs are also used by Herzberg for vision therapy, notably in cases of kids with esophoria, with successful results.

He also fits seniors. "Recently, we fit a 69-year-old woman with VFLs. She was getting a neck ache by tilting her head back when viewing her computer screen through her general purpose PALs. The VFLs relieved her neck ache and gave her a wider field of vision at the near and intermediate."

Just as important as taking a thorough patient history that focuses on general workplace and leisure tasks is detailing the specifics of how patients use their eyes during work and play, points out Joseph Black, an optician at Eye Associates of Boca Raton in Boca Raton, Fla.

"Variable focus lenses are most often a second pair of eyewear--an additional financial investment for patients--so it's important to find out every nuance of the eyewear's expected use to match the right prescription and product to their need," Black says.

For example, Black points out, "I've found that variable focus lenses work better for desktop computers than laptop computers. Road warriors who primarily use a laptop when traveling may not benefit from a VFL as much as an office worker, because laptop screens are set closer and lower.

When keying in a refraction, prescription, measurements, and lens and frame fitting, Black says he finds out whether the patient will be using a desktop or laptop computer most of the time to find the best product for that particular distance.

When determining who is right for the product, Black says that he is selective about to whom he presents VFLs. He has had the most success with "cube sitters," usually under 40 years old.

He bundles VFLs as a second pair to accompany general purpose PALs or single vision distance lenses (depending on if the patient requires presbyopic correction), and also offers VFLs in a third-pair package with polarized sunwear or sun clips plus the primary eyewear.

CURRENT DESIGNS

Many of today's VFLs feature aspheric designs with flatter base curves, resulting in thinner, flatter, lighter-weight
lenses with less visual distortion.

Several companies tout asymmetrical design, which features true right and left lens designs, as opposed to symmetrical design, which uses one lens for both right and left. And most companies offer two versions of VFLs: One for wearers of around +1.50, +1.75D or less add powers, and one for powers over +2.00D, with a set power decrease in each.

Several VFLs allow a viewing range of approximately 12 inches to 10 feet, while others offer a viewing range of just over one foot to 10 feet. Some VFLs feature an area for distance viewing, as well.

Key to a wearer's visual comfort is the VFL's longer, wider corridor. In order to take full advantage of this, VFL measurements place the fitting cross at the center pupil. Dot the lens at the center of the pupil, and take monocular PD measurements with a pupilometer. The longer corridor allows the wearer to experience every change of power throughout the corridor for an extended viewing range, while also taking advantage of the wider field of view. To achieve this, VFLs require a minimum B measurement and/or seg height.

	Computers can cause eyestrain and result in CVS. Shown Shamir's Office lens

Recent VFL introductions include short corridor designs which allow fitting heights of around 16mm to accommodate smaller frames.

Frames should be pre-fitted prior to lens measurements, with pantoscopic angle typically between 7 and 12 degrees, vertex distance of 10mm to 12mm, and comfortable face form/ curvature.

It's always best to check with the manufacturer for its variable focus lens specifics, including viewing distances and fitting and measuring procedures. Your wholesale lab can also be a great resource. Both can supply literature on VFLs, and many will also have educational programs available. Don't hesitate to speak with other dispensers to see what VFLs they are using and why.

VFLs compliment general purpose PALs, which supply an everyday, all- distance visual solution. But general purpose PALs are not designed for task-specific activities, and typically can't offer the same visual comfort for computer use and other intermediate-to-far visual needs that a VFL can with its customized Rx and wider field of view in near and intermediate zones.

Often, general-purpose PAL wearers--like flattop bifocal and trifocal wearers--have to tilt back their heads to view the computer screen or arrange paperwork just so for easier viewing with limited head movement.

A variable focus lens is ideal to replace conventional reading lenses because it offers many features and benefits that today's patients are looking for; that is, reading, computer viewing, and intermediate working distance--all in one lens.