Article Date: 11/1/2011

Provide Night Sight
instrumental focus

Provide Night Sight

Refractive device enhances night vision.

Tara Rosenzweig, Contributing Editor

For many patients, nighttime driving requires cruising below the speed limit, squinting or avoidance altogether. A new refracting system is now available to take both the squint and scare out of night driving. It's called the PSF Refractor, from VMax Vision.

Here, Mile Brujic, O.D., of Bowling Green, Ohio and Jim Owen, O.D., of Encinitas, Calif., discuss the device.


The PSF Refractor uses point-spread function by measuring a patient's subjective visual response to a point source. This enables the correction of higher-order aberrations and results in precise refractions. Some patients have the ability to discriminate to a level of 0.05D differences. This ultimately translates into an accurate and reliable lens prescription that may enhance a patient's nighttime driving perception, Dr. Brujic explains.

“With letter acuity, I will sometimes hear patients say while viewing a single line of letters, ‘one of the letters is clear, but another letter looks blurry,’” he explains. “The PSF Refractor eliminates the variability of individual letters, as it has the patient just focus on a very specific, precise target.”

To complement the refraction's accuracy, VMax Vision offers Encepsion lenses. The ophthalmic lenses are made using 100% digital free-form DiamondPoint Technology for an accuracy of 0.05D. The lenses are available in single vision and PAL in all lens materials and accommodate all frame types, the company says.

“I tell my patients, ‘Digital ophthalmic lenses made from the same company that made the refraction device are now available, and they are as precise as the refractive device,’” explains Dr. Owen. “Then, I hand the patient off to my optician and say in front of the patient, ‘I've talked with Mrs. Jones about the Encepsion lenses … ’ and my optician takes it from there. Because patients are so impressed with the clarity of their new prescription, more often than not, they opt for the VMax lenses.”

Testing procedure

To start, the PSF Refractor performs an auto-calibration on itself every morning before patient use. Next, the patient sits behind the device and looks through it, as they would a set of binoculars. Instead of a line of letters, the patient sees a white dot (e.g. the target, or point spread function) within a black circle that has small lines radiating from it. Now, you enter the patient's prescription into the device, and instruct the patient to tell you the lenses that make the small white dot appear more focused, Dr. Brujic explains.

“To change the device's lenses, you use the roller ball of its mouse, rolling the ball up for plus powers and down for minus powers,” he says.

Dr. Owen adds that as more minus power is added, the target becomes blurrier, so the device can help O.D.s avoid over-minusing errors.

The PSF Refractor is comprised of four tests that identify the patient's best prescription. The first test reveals sphere power, the second test determines axis orientation, test three reveals cylinder power, and test four finalizes the patient's sphere power.

The test time varies from 45 seconds to three-and-a-half minutes, depending on the patient, but most patients are refracted within a minute-and-a-half to two minutes per eye, Drs. Owen and Brujic say.

“When I complete the fourth test, I really enjoy showing patients their habitual prescription compared to their new prescription based on the PSF Refraction results” says Dr. Brujic. “Patients are often times surprised by the level of difference and impressed we are offering them this technology.”

Once the patient has completed the test, the results can be entered into the patient's record.

The PSF Refractor uses pointspread function by measuring a patient's subjective visual response to a point source. This enables the correction of higher-order aberrations and results in precise refractions.


“A company representative hooks up the device and sits with you for a couple hours to walk you through how to perform refractions using this device,” explains Dr. Owen. “Then, the rep spends time educating both you and your opticians about the Encepsion lenses and how to measure these lens types.” VMax Vision also provides Encepsion merchandising materials for the office, the company says.

Return on investment

The PSF Refractor costs between $25,000 and $45,000 depending on Encepsion lens commitments. VMax Vision also offers a fee-per-use plan, the company says. (Contact the company directly for more specifics.) Use CPT code 92015 (refractive service) for reimbursement. Given that refraction is a standard component of the comprehensive vision exam, your ROI is fast, say Drs. Brujic and Owen.

Dr. Owen adds that offering VMax's Encepsion lenses, which cost between $500 and $700 a pair buffers one's ROI.

“If you can dispense just one pair of these per day, you're reaping immediate financial rewards,” he says.

Something else to consider: Identifying and providing a solution to your patient's nighttime vision complaints can instantly increase your profit up to 30%, according VMax Vision.

“Patients are telling me, ‘my distance vision has never been this clear,’ and ‘I've never seen in the evening the way I do with these lenses,’” says Dr. Brujic. “This device is truly changing conventional refractive endpoints and filling an unmet need that exists for so many patients.” OM

* Drs. Brujic and Owen speak on behalf of VMax Vision's PSF Refractor, though have no financial interest in the company.


Optometric Management, Issue: November 2011