THE BUSINESS OF PD
Probably no question elicits more surprise and emotion from eyecare professionals than when they’re asked: “Can I have a copy of my Rx and PD?” Why? Because this innocent request means they’re losing a bit more of their historical “control” over the sale of prescription eyewear. If we step back and take a longer perspective, we see that this query is just the latest manifestation of a consumer empowerment process that began more than three decades ago. In 1977, reacting to a rising tide of complaints that consumers were having trouble comparing eyewear prices because their eyecare providers were reluctant to give up their prescriptions, the Federal Trade Commission took decisive and corrective action by issuing Eyeglasses I, also known as the Spectacle Prescription Release Rule. Twenty-five years later, the FTC addressed a similar situation for contact lens wearers through the Fairness to Contact Lens Consumer’s Act. Importantly, both of these rules were designed to pry open an industry seen as unfairly acting in its own self-interest.
Fast forward to today, with the arrival of prescription eyeglasses offered online, and consumers find themselves once again squaring off for battle with their eyecare professional. This time, they’re asking their state officials for help in freeing their PD from their local eyewear establishment.
THE BATTLE FOR THE PD
Eyecare professionals argue that the pupillary distance is not a prescription parameter mandated for release under Eyeglasses I. Consumers counter that only by having the Rx and their PD will they be able to freely shop the eyewear market, which was the intent of Eyeglasses I. ECPs respond that by releasing the PD to a supplier outside their office, consumers are in essence removing them from responsibility as eyewear’s “general contractor,” leaving unanswered the question of who is ultimately accountable for ensuring product quality, prescription efficacy and overall visual comfort. Additionally, eyecare professionals admonish that by sourcing prescription eyewear online, consumers are separating out important try-on, consultative, fitting, warrantee and other services that form the majority of the added-value and increased cost represented in their higher asking prices. ECPs are seeing an obvious message here: If you pay less, you get less.
But as household discretionary income comes under greater downward pressure than ever before, consumers today are actively vetting the value they receive for every dollar spent. It’s no secret that the public views eyewear prices as arbitrarily high, and a recent CBS “60 Minutes” segment supports this sentiment. By referring to glasses as “just a few pieces of plastic,” reporter Leslie Stahl reinforced three things: 1. This phrase has great resonance with consumers. 2. ECP efforts to communicate their added value have been unsuccessful, and 3. Consumers willingly respond to seeing brick-and-mortar opticals as “greedy middlemen.”
THE NEW AGE CONSUMER
Striving to obtain maximum value, shoppers today are increasingly willing to experiment with making trade-offs to enjoy lower prices. But even as this new economic paradigm begins to impact the optical industry, most optical store owners have yet to begin to strategize how they will cope with this far more vigilant consumer. Unfortunately, by neglecting to outline even a simple fee schedule for servicing eyewear purchased outside their office, eyecare professionals have ended up creating a climate of resentment for both themselves and their patients.
Today, as a consumer’s desire to free their PD runs smack into an eyecare professional’s reluctance to hand it over, it’s time to take an in-depth look at all the issues surrounding this new skirmish. We’ll begin by exploring the business of making money in optical.
The business of eyecare is comprised by various revenue generators:
1. Eye Exam Fees—including diagnostic fees, up to 25 percent.
Procedure fees—various treatment regimens, including those for dry eye,
eye training, vision training, etc., up to 20 percent.
3. Prescription eyewear and sunwear—eyeglasses can deliver up to 50 percent of the gross profits for most practices.
Contact lens exams, follow-up visits and replacement lenses—healthy
practices can achieve 20 percent of their gross profits in this
5. Plano sunglasses and accessories—typically less than 5 percent of gross sales.
6. Eyewear service, repair and adjustment fees—yet to be determined.
the sale of eyeglasses is the greatest revenue generator for optical
stores. But you can’t generally start the sale of glasses without first
having an Rx. And Rx exams are financed primarily by participation in
vision care plans (VCPs). For most consumers, the scheduling of exams
and determination of eyewear allowances is initiated through the VCP’s
logistics. With plan benefits usually timed to infrequent one or
two-year intervals, it’s easy to see why leveraging an exam visit into a
pair of revenue-generating eyewear is important. So when an Rx appears
to be walking out the door, business owners see the single most
important contributor to their bottom line walking right out with it.
the attraction of low prices available online, consumers are beginning
to question why their “trusted” eyecare professional is charging more
for what appears to be the same product. And contained within that one
word—product—is IMHO, the biggest mistake the optical industry has ever
made. By bundling all the consultative, fitting, adjustment, warranty
and other services into a one-price, product-centered transaction, ECPs
did themselves and their patients a great disservice. Without a separate
pricing schedule of services covering adjustments, minor repairs,
replacement parts, warranty coverage, etc., included in the asking price
of eyeglasses, consumers were left with only the eyewear product alone
with which to compare prices and gauge value.
SMELL THE COFFEE
within an insulated environment for years, ECPs had grown comfortable
and complacent, with little motivation to face the realities of the
changing marketplace. Although the arrival of big box chains in the
1980s did bring independents their first real taste of competition, ECPs
were slow to begin adapting to the new disrupter in their midst. Today,
new and alternate channels of distribution for Rx eyeglasses are
beginning to spring up and capitalize on the ECP’s mistaken assumption
that its customer base had always understood and appreciated all the
services covered in the cost of their glasses.
POLITICS AND THE PD
dispensing of prescription eyeglasses, a Class 1 medical device, has
been regulated in part by some state requirements that a licensed
optometrist or optician oversees the process of dispensing. Being a
medical device, any records kept by ECPs are therefore considered
medical records, and as such, must be made available to the patient on
demand. Naturally, this could also include the patient’s PD. Even in
light of this, consumers continue to encounter difficulties obtaining
their PD when requested. Therefore, the question of what a consumer is
rightfully entitled to in their eyeglass record is far from being
conclusively answered. But as consumers become comfortable with buying
other types of medical products online, they’re beginning to ask their
government representatives whether the sale of prescription eyeglasses
requires regulatory oversight at all.
PRODUCT SAFETY AND REGULATION
safety and efficacy are important concerns for both consumers and
eyecare professionals. But the dispensing of eyeglasses by opticians,
however, is still only licensed in less than half of all states.
Although the FDA ensures that consumers face reduced risk from the
consequences of compounded injury with the impact resistance
requirement, they have not instituted regulations addressing the belief
that eyewear lacking compliance with industry standards for power or PD
can cause harm.
In our current regulatory environment, efforts to
control costs and limit government involvement are constantly under
scrutiny and review. Today, regulations are increasingly vetted toward
optimal balancing of cost versus risk of harm. This is the main metric
for determining the degree of oversight, regulation and recommendation
for medical drugs, tests, procedures and devices. Notwithstanding
anecdotes that ECPs recite about patients who needlessly suffered from
poorly fitted or mis-fabricated eyewear, there remains a distinct lack
of consensus or hard evidence of the risk of long-term harm accompanying
poorly made eyewear. And hard evidence is what regulators need to
substantiate hard regulation.
EVIDENCE-BASED RISK ASSESSMENT
2005, the Canadian Ophthalmological Society issued guidelines for the
frequency of oculovisual examinations, including those exams intended to
screen individuals for eye disease, provide secondary control of
existing disease or tertiary prevention in reducing the consequential
harm of chronic disease. In developing their guidelines, the COS
employed real-world, evidence-based risk assessment studies. Here is a
short excerpt of their surprising conclusions:
“Healthy adults, who
do not notice anything wrong with their eyes, should see an eye doctor
according to the following schedule: ages 19 to 40—at least every 10
years; ages 41 to 55—at least every five years; ages 56 to 65—at least
every three years; and over age 65—at least every two years.”
note that within these same recommendations, the COS cited sufficient
data to recommend at least one complete eye exam for children before age
5. Meanwhile in the U.S., only three states—Kentucky, Illinois and
Missouri—have seen fit to mandate a complete eye exam before a child
EVIDENCE VS. BELIEF
with evidenced-based harm in hand, regulators today often find
themselves coming into conflict with the public’s “common sense” beliefs
about what constitutes acceptable risk.
For example, a few years
ago, the New York State Commissioner of Motor Vehicles attempted to
streamline the licensure process by reducing the DMV’s frequency of
vision screening from once every eight years via a licensed eyecare
professional to just a single test performed at initial licensure, with
self-certification done at renewals thereafter. DMV officials in New
York state had reviewed statistics from nearby Connecticut and
Pennsylvania, who for years had been using a single vision screening
done at initial licensure. While data is currently lacking that would
help define the contribution of poor vision to car accidents, the real
world evidence was clear: No statistically significant differences
existed in accidents or injuries between states that regularly tested
acuity and those that don’t.
As the Commissioner’s plan was
unveiled, public pushback was swift and decisive: New York drivers did
not want others sharing the road without a periodic vision test.
Subsequently, the governor of New York instructed his DMV Commissioner
to rescind the new proposed screening schedule and return to the
previous eight-year screening model. Here, despite evidence of little
risk, the court of public opinion had spoken loudly and clearly.
we look at the dynamics of oversight for prescription eyewear
worldwide, we note how the regulatory atmosphere is changing with the
arrival of online prescription eyewear. For example, in 2010, the
Canadian Health Minister in British Colombia, responding to a court case
involving a prominent online optical retailer, was prompted to review
the current regulations concerning eyeglasses contained in the
applicable Canada’s Health Professionals Act. Subsequently, changes were
instituted to allow B.C. consumers to order eyewear online without
providing the seller a copy of their prescription. The new regulations
stipulated that all patients must be given a copy of their Rx for
free—regardless of whether requested or not. Commenting on these
changes, the Health Minister noted: “With advances in technology and
more consumers turning to the Internet, it makes sense to modernize a
decades-old system to give British Columbians more choice.”
THE END OF PRIMACY IN PD
the legalization of the sale of over-the-counter reading glasses in the
late 1980s, the decline in the importance of accurate pupillary
measurement had begun. Some states tried to limit the perceived risks of
OTCs by forbidding the sale of powers over 2.75 diopters. But is this
anything more than a superficial gesture, based on a “feeling” that
consumers needing stronger powers should be seeing an eye doctor? As far
as the potential negative effects of inaccurate PDs in OTCs is
concerned, a 2009 OTC reading glass study concluded that most spectacle
wearers would tolerate “up to 0.50D vertical prism (imbalance) and up to
1.0D horizontal prism (imbalance)” without marked discomfort.
as OTC reading glasses approach $800 million in sales and more than 46
million units sold annually (Source: Vision Watch 2012), it is clear
that consumers are willing to trade imprecise centering in return for
low price. With little hard evidence to the contrary, lawmakers are left
with little choice but to continue to allow the sale of these “PD-less”
BEWARE OF PD BACKLASH
resisting the release of prescriptions in the past, eyecare
professionals discovered firsthand what happens when consumers profile
them as unreasonably trying to control the sale of optical products.
Recently, ECPs have attempted to re-close the system by carrying only
those products or brands not readily found online. But in the case of
contact lenses, where companies have touted to ECPs that their lenses
are not readily available online, another backlash is brewing as
consumers once again see ECPs trying to steer their freedom of choice.
Although good practice management advises that ECP keep metrics on both
capture ratio and prescription hand-off, these terms may, in an age of
Internet transparency, invite misunderstanding if taken out of context
by consumers. This could further impact ECP credibility.
moral for eyecare professionals: Think twice before withholding a
patient’s PD, even if state laws and regulations are on your side. We
live in an era increasingly dominated by the power of social media, and
the court of public opinion is not one to be taken lightly.
PD AND THE CONSUMER AS KING
our political system, consumers are not always active participants.
Nevertheless, government officials recognize their potential influence
can be great if an issue surfaces with enough sizzle to stir voters out
of bed on Election Day. It’s clear today that lawmakers increasingly
tend to consider regulatory issues before them in “consumer-friendly”
terms. In Utah, for example, legislation is pending that allows
“alternate channels of distribution” for medical services that were
previously done only by licensed professionals. There, as consumers
increasingly feel comfortable taking their own blood pressure and heart
rate in a kiosk at the local mall, lawmakers are considering that
contact lenses and even eye exams could be made available in a similar
Only a few states including Alaska, Arizona, Kansas, Massachusetts and New Mexico mandate that a PD be entered on every eyeglass prescription. But if eyecare professionals continue to
ignore the growing demand for freedom of choice in buying prescription
eyewear, they might just see their state officials become both consumer
advocates and professional adversaries. More than ever, eyecare
professionals must reformulate their business strategy to successfully
compete in an economy where consumers are infatuated with the low
prices, wide selection and convenience of online.
A Primer on PD Tech
Ask any eyecare professional if accurate PDs are important in satisfying an eyewear consumer, and they’ll no doubt respond with an overwhelming chorus of “Yes!” But hanging your professional hat on the hook of PD’s primacy today is a risky undertaking. To better appreciate a PD’s nuanced and multilayered character, let’s take a look at the science, anatomy and measuring techniques surrounding
the pupillary distance.
Quite a bit of research has been done into the science of pupillary measurement. The importance of needing to define the extremes, age and gender distribution of PDs can be found within the disciplines concerned with stereoscopic displays. Here, whether considerations are binocular or bi-ocular (two eyes sharing the same entrance pupil), knowledge of the range to be accommodated is essential in designing these devices. Because of this, almost all PD research concentrates on the importance of binocular rather than monocular values. Here is a short summary of their findings:
- Extremes for all adults (Age 18 and over): 45-80 mm
- 95th Percentile for all adults: 70 mm and below
- Minimum values for children (Ages 0 to 5): 30-40 mm
- Mean and median adult PD (all races and sexes included): 63 mm
- Changes most from birth to age 5 (up to 10 mm growth).
- Reveals second greatest change from ages 5 to 18 (up to 7.5 mm).
- Slowing in females at age 14; males at age 18, reflecting earlier female maturation.
- Average is smaller in females than males.
- Continues to change between the ages of 18 to 50 with most of the delta occurring in ages 18 to 30, and the average change is 3 percent.
- Changes more slowly in the age group over 60 (up to 1.2 mm).
THE METRICS OF PUPILLARY DISTANCE
By definition, the taking of a PD suggests that we are determining the distance between the eye’s pupils. But within the last 20 years, as the optics and sophistication of eyeglass lenses have tremendously advanced, ECPs have started to improve their understanding of how designers use references beyond simple pupil location to help optimize a lens’ acuity, comfort and utility.
Pupillary axis: A line drawn perpendicular to the corneal surface through the center of the eye’s (entrance) pupil.
Visual axis: This is the actual sight line of the eye, running from center of the fovea, through the eye’s nodal points and out to the object of regard. This is where the brain is actually looking. Because the fovea is displaced temporally from the intersection of the pupillary axis with the retina, the corneal reflection axis is normally found approximately 3-5 degrees nasal of the intersection of the pupillary axis with the cornea. The angle between these two axes is known as angle kappa and has linear values at the respective corneal and spectacle planes (VD = 13 mm) of approximately 0.25 mm and 0.50 mm.
Corneal reflection: Also known as the corneal reflex, it is the image formed by a light source shining upon the cornea. If the examiner is co-axial with this light source, then the position of corneal reflection marks where the visual axis exits the eye. This is important for determining prismatic effects and optimizing placement of a progressive lens’ intermediate corridor.
Center of rotation: This is the virtual point around which the eye appears to rotate during its excursions. Its importance in lens design is twofold: It allows designers a proper reference for optimizing a lens’ off-axis performance, and it is essential for maximizing binocular performance within a pair of lenses. A line drawn from the object/fixation point through the CR (center of rotation) is called the fixation axis. The CR provides a stable framework for the comparison mapping of corresponding points on each eye’s retina. Specific equipment, Rx parameters and other anatomical factors are required to assess the precise location of the center of rotation.
For eyecare professionals, it wasn’t until the arrival of progressive lenses in the 1960s that the importance of an accurate monocular PD for obtaining optimal intermediate and reading utility was fully appreciated. Before that time, measurements primarily centered on obtaining binocular PDs. Using a millimeter ruler, monocular values, if desired, were derived by halving this value.
MEASURING METHODS AND ACCURACY
Several studies in the last 20 years have attempted to scientifically analyze the accuracy and repeatability of obtaining PDs using three primary methods:
- PD ruler: Used to measure the distance between pupils, corneal reflections, iris margins and particularly in the case of small children, the inner and outer canthus. A study completed in 2002 assessed that the ruler method can yield values accurate to within 1.54 mm of a “gold standard” (see below) with 68 percent confidence.
- Pupillometer: Primarily measures the distance between corneal reflections. Overall values were found to be within 0.74 mm accurate with 95 percent confidence.
- Digital centration devices: These may use either corneal reflections or iris borders for determining PD. The user should be aware if the device’s software employs an internal calculation to extrapolate at the visual axis location from the pupil/iris center. DCDs were found to be very accurate instruments, with binocular PDs found to be within 0.40 mm with 95 percent confidence.
There’s a pattern here: Pupillometers appear more accurate than millimeter rulers and digital centration devices appear more accurate than pupillometers. But before you ditch your PD ruler, remember that the ruler and manual measurements will always play an important role in an ECP’s toolkit. Both objective and subjective verification and trouble-shooting of prescription eyewear will continue to require expertise in the use of ruler and pen. Because of this, some practitioners prefer to use an enhanced manual method, which employs a mirror to subjectively determine the visual axis at the spectacle plane. Each method has to consider variables that may impact accuracy and efficacy. Below is a summary of the most important factors affecting pupillary measurement:
- Device calibration: While obviously important when using instruments, parallaxic errors can arise when using the ruler method if there are differences between the PDs of tester and subject. These are avoided by using Jalie’s Rule of Sixteenths, which states that every millimeter difference PD requires an adjustment of one-sixteenth millimeter to the end result.
- Instrument operator skill/experience:
- Repeatability—can a single operator take several similar measurements from the same patient?
- Serial—can multiple operators take similar measurements from the same patient?
- Near and intermediate considerations:
- Vertex distance—generally based on an average value of 13 mm. However, if the fitted VD departs from this number by 4 mm or more, then values for near and intermediate use will not be optimal without recalculation.
- Pantoscopic tilt—improperly measured values can result in deviations that may require compensation.
- Frame considerations: A person’s physiognomy or fitting preference may place the frame markedly off the facial median plane, a deviation that can make the efficacy of the found values suspect.
- Head cape: Defined as the habitual departure from the orthogonal facial plane, head cape compensation is important for both optimal binocularity and multifocal utility.
- Rounding errors: Present in all methods, rounding errors can affect accuracy.
- Patient cooperation: This is one of the least controllable of all variables affecting PD measurements.
THE GOLD STANDARD IN PD
In the 2009 study, eight different devices, both pupillometers and DCDs, were used to help answer an important question: Considering all the variables affecting a PD measurement, can we be confident that using any method or instrument will result in the complete truth of a precisely accurate PD? The answer is no. Faced with determining the truth of an objectively unverifiable parameter, statisticians often turn to averaging all the measurements to a mean value, and then observing the distribution of all the values found to this mean. This “best possible compromise” is then referred to as the gold standard. The 2009 study sought to establish both device repeatability (nine subjects tested in five rounds by eight different instruments) and serial consistency (80 subjects measured once by eight different instruments). When the data was adjusted for various corrective factors, the average for all devices was found to be within 0.6 mm of the gold standard with 95 percent confidence. That’s accuracy I’d take any day.
L&T contributing editor Barry Santini is a New York State-licensed optician based in Seaford, N.Y.