To adjust or not to adjust

OT  investigates Adlens’ two self-adjustable products and its controversial attempts to change the Opticians Act

Adlens self-adjustable lenses

Oxford-based adjustable lens manufacturer Adlens believes it has the two products that patients have been waiting for.

The company has developed two varieties of spectacles that it says will take care of many presbyopes’ short- and long-term needs. Adlens’ more recently released technology – only available in the US – puts an adjustable fluid-filled dynamic lens on top of a prescription lens set for the wearer’s distance vision.

The other, low-cost variety – first sold in Japan in 2011, then the US and several European countries – utilises two lens plates that slide over each other at the turn of a dial. These ‘Alvarez’ spectacles are the eyewear that Adlens hopes to sell over the counter in the UK if an amendment is made to the Opticians Act.

The company was bolstered by the support of some members of the House of Lords for a proposed amendment allowing adjustable lenses of between +4 and -6 diopters to be sold over the counter, when Lord Newby raised the matter in February.

The Government has indicated it has no plans to change the legislation governing optics – and any change would require its support. However, Adlens will continue to lobby for the change with the Department of Health, the company’s chief medical officer, Dr Graeme Mackenzie, told OT.

Some have suggested the technology’s proponents would be better placed to seek approval in the UK for adjustable spectacles to be sold within the current range of powers allowed for over-the-counter reading glasses, but in June, Lord Newby introduced his private member’s bill for a proposed amendment with negative-powered lenses included.

The General Optical Council (GOC) commissioned an independent report by Professor Neil Charman of the University of Manchester and also asked its standards committee for its position on a change, as requested by the Department of Health in order to advise health ministers.

"All the research that applied to reading glasses applies to us"

However, Adlens believes that the GOC is the one to “take the lead” on the decision, and argues that it has displayed “bias – embarrassingly so, as pointed out by others,” not the independence required of a regulator, Dr Mackenzie said.

The GOC has responded that it has not lobbied either for or against the proposal, but provided the assistance that the Department of Health requested. “Any accusation of bias is completely without foundation,” a GOC spokesman said.

With the opposition to a change in the legislation shown by many practitioners, OT sat down with Adlens to discuss some of the concerns around such over-the-counter sales.

Concern: Offering over-the-counter spectacles with negative powers would cause a reduction in eye tests and a consequent increase in undetected eye disease.

Adlens reply:

The precedent of changing the law in 1989 to allow reading glasses to be sold over the counter contradicts such a prediction, Dr Mackenzie believes.

Looking at the data, there appears to be no change in the number of eye examinations, he said.

“There were two events that had a big impact on the number of eye examinations taking place, the first was when optometrists started charging – a big drop, but it recovered. The other was an increase in eye examinations in Scotland when they made eye examinations free,” Dr Mackenzie emphasised.

"It is likely that some of those purchasing variable-focus spectacles might feel that...there was no need for further action regarding their vision"

He said that more research into why people avoided eye examinations would shed light on the issue, adding: “There is no evidence that the way to make people get their eyes examined is by forcing them to do so through the restriction of product.”

However, Professor Charman refuted Adlens’ argument in his report on the technology but also agreed that more research was needed.

“[The increase] may simply reflect changes in the absolute numbers and age distribution of the population … Had no ready-readers been available, the increase in eye examinations might have been even greater,” he noted.

He also noted that myopes might be at more risk of harm if they do not have regular eye examinations.

On the issue, Professor Charman concludes: “It is likely that some of those purchasing variable-focus spectacles might feel that, since they could see reasonably clearly, there was no need for further action regarding their vision.”

Concern: Wearers may adjust to the wrong power, with worrying immediate consequences for sight and safety.

Adlens reply:

A number of studies have been conducted looking at how well people do at getting the correct power when self-adjusting a lens. The standard Adlens set itself was users adjusting to within three-quarters of a diopter of the correct power, the typical accuracy for optometrists, Dr Mackenzie stressed to OT.

Approximately 1000 Chinese children, aged 11–16, were given fluid-filled self-adjusting spectacles and the power they adjusted to was compared to that resulting from a cycloplegic subjective refractive test. “[The children] were, on average, as accurate as an ophthalmologist,” Dr Mackenzie said.

Similar trials have shown comparable results. However, Professor Charman noted in his report that a small number of participants, when doing multiple adjustments, had up to one diopter’s difference from the first adjustment to the second.

“Overall, self-selection of correcting power yields good levels of agreement with clinical subjective findings for a high proportion of eyes … Nevertheless, self-selection leads to a significant subset of individual eyes being poorly corrected, particularly among higher myopes and astigmats,” Professor Charman wrote in his report.

This British Medical Journal-published trial has not been conducted for each type of adjustable-lens technology, with no similar research on the Alvarez spectacles, for example.

Adlens said that the results of these trials holds true for all the different adjustable lens technologies, as passing a driving test in one car meant you were safe to operate any model of vehicle.

However, this has been disputed by one of the scientists involved in the Chinese study, Dr Joshua Silver.

The founder of Adlens, who has since left the business, told OT that: “While this might perhaps be the case, such a claim cannot be made without scientific evidence.”

Adlens wearer

Concern: The distorted peripheral vision of the Alvarez lens, or a set of poorly adjusted spectacles, could make a driver more prone to accidents than other visual correction products.

Adlens reply:

The current law accepts the risk that hyperopes may drive with self-selected over-the-counter reading glasses, so in fairness, the same argument should hold for myopes driving with over-the-counter adjustable lenses as well, Dr Mackenzie said.

“People with far-sightedness use reading glasses for driving, because they can … All the research that applied to reading glasses applies to us.”

The company also went a step further, and funded a study looking at hazard detection using the Alvarez frames, conducted by the University of Michigan.

Dr Michael Flannagan told OT that he tested the vision of front-seat passengers under “rich and realistic” road conditions, both during the day and at night.

A driver wearing their prescription spectacles can detect a hazard at an average of 93m with their prescription eyewear, 91m when self-adjusting their Adlens over-the-counter product, and 31m with no eyewear at all.

Dr Flannagan told OT that: “There were no important differences between the adjustable eyewear and prescription eyewear.”

Dr Flannagan planned to put the Alvarez lenses through more trials in the future, looking at the eye wear’s sensitivity to glare in darkened environments and test subjects’ driving ability on test tracks, he highlighted.

Concern: Over time, a patient using lenses with an incorrect power for their vision might accelerate their visual issues, especially young myopes.

Adlens reply:

The proposed UK law change would restrict the use of the adjustable lenses to people aged 16 and over. The product is also meant for temporary use, and customer surveys from Japan and the US support this, Dr Mackenzie explained.

“People don’t want to wear our glasses all day. Even though you can function just fine in them, and you’ve got good acuity, they are not the most comfortable pair of glasses to wear on a day-to-day basis. That’s why we’ve always been very clear – this is a temporary solution.”

He added: “These are not glasses people wear outdoors, unless they have to. If they do wear them outdoors, it’s because their prescription spectacles are broken, or it’s because they’ve just realised they needed spectacles and are waiting for a prescription pair.”

Adlens Alvarez

A safety sheet, highlighting the visual errors that the lenses are unsuitable for as well as the importance of eye tests, is included with each pair sold.

Professor Charman’s report concluded that lenses with incorrect powers were unlikely to cause severe harm in adults, but the risk was more likely to be significant for children, with their long-term vision and development potentially harmed.

He also described the optical quality of the Alvarez lens as “basically satisfactory.”

Dr Mackenzie said that new optical technologies have long met resistance from the industry concerned about potential safety issues. He added: “Ultimately, the question that wins out is: is the risk outweighed by the benefit to the public?”

Concern: Negative-powered lenses are restricted for over-the-counter sales because myopes are at a higher risk of developing sight-threatening pathologies than hyperopes if they don’t have regular eye examinations.

Adlens reply:

Myopic maculopathy is a more serious condition, being untreatable, than the pathologies such as angle-closure glaucoma that hyperopes are at increased risk of, Dr Mackenzie conceded.

“But think about the availability of aspirin, paracetamol, any over-the-counter drug in the world – there’s a far greater risk associated with any of those,” he argued, adding: “What [doctors] realised was that not having to prescribe paracetamol to people freed them up to do more important jobs. I believe similar good, unintended consequences will come from the deregulation of eyewear.”

However, in his independent assessment, Professor Charman was concerned about higher myopes not having regular eye examinations. He explained: “Although all individuals would be at risk of suffering from undetected pathology, the dangers would be higher in myopes, particularly higher myopes. This might suggest that self-selection should be confined to the correction of only low myopic errors, emmetropic or hyperopic errors.”

"Most users use them like a pair of 'super readers' around the house, for computer use"

The General Optical Council (GOC) commissioned an independent report by Professor Neil Charman of the University of Manchester and also asked its standards committee for its position on a change, as requested by the Department of Health in order to advise health ministers.

Concern: In a country with good access to optical professionals and products, the customer demand for an over-the-counter product is insufficient to change the law.

Adlens reply:

Dr Mackenzie said there is a need for temporary correction – from people who have lost or broken their spectacles or contact lenses and are waiting for a replacement, to people who are experiencing fluctuating vision following cataract surgery.

“Most users use them like a pair of ‘super readers’ around the house, for computer use.”

Speaking about wearers with astigmatism, he emphasised: “Is it better to have a spherical-equivalent correction which is not quite perfect but better than nothing at all?”

He has “never come across” a user who replaced their prescription spectacles or contact lenses completely with the Alvarez product.

Adlens has also pointed out itself – a point also raised by Professor Charman – that the mismatch between interpupillary distance and optical centre distance in the spectacles can create uncomfortable prismatic effects from prolonged wear.

The GOC standards committee expressed concerns that post-surgery cataract patients would use the spectacles to drive rather than consulting their optometrist, who would be able to assess if they were safe to drive or not.

Professor Charman’s report was supportive of adjustable spectacles with positive powers.

He summarised: “In the spirit of the present regulations, there would appear to be no fundamental reason why adjustable ‘reading’ spectacles with pairs of lenses with positive power variable within the range 0 to +4 diopters should not be made available as an alternative to currently-permitted over-the-counter devices having pairs of fixed power lenses within the same range.

“The availability of independent adjustment of the two lens powers within this range would be helpful to anisometropes,” Professor Charman added.

Concern: While one company might offer an adjustable product safe for users to buy over the counter, a law change could open up a slippery slope by allowing any company from anywhere in the world to sell adjustable or non-adjustable products with negative and/or positive powers over the counter.

Adlens reply:

The proposed law change will stress that over-the-counter products with negative power must be adjustable to be legally sold, Dr Mackenzie emphasised.

He explained: “You can’t do the same thing with a fixed lens power, simply because … how do you stock, in a Primark, the 1000 pairs of glasses needed to cover the entire range? That was a big reason why readers were restricted to a certain range.”

However, Professor Charman concluded in his report that if adjustable lenses outside the O–+4 diopter range were approved, sales of fixed spectacles within the same range would also need to be permitted for the same purpose.

However, Dr Mackenzie warned that offshore optical companies will soon be able to directly offer a consumer a pair of glasses tailored to their refractive error completely through a website, circumventing entirely the national trade restrictions requiring a prescription.

He added: “It’s coming. The question is: are optometrists going to spend the next 10–15 years trying to protect their trade or are they going to figure out how to use these tools to enhance their profession?”

The odd couple

Self-adjusting like the 'Alvarez', Adlens 'Focuss' spectacles offer additional benefits – such as attractive frames

Adlens wearer

Adlens’ other, odd-looking product may be getting all the press – but the company believes its newer spectacles offering more natural vision within attractive spectacles are the real game-changer.

The ‘Focuss’ spectacles will be sold via prescription, as they comprise both a static prescription lens for the wearer’s distance vision and an adjustable lens to switch to reading and middle-ground vision.

Twisting the dial applies pressure to the sides of a patented flexible membrane, which changes the spherical power of the dynamic lens between the three customised settings.

Unlike the ‘Alvarez’ lens used in the budget Adlens brand, the power is consistent across the whole lens, with minimal peripheral distortion in the company’s fluid-filled spectacles range.

The ‘Focuss’ spectacles – prices start from US $1250 (£865) – will be delivered through the existing spectacles infrastructure of ophthalmic laboratories, Dr Mackenzie said.

Adlens chief technology officer, Dr Rob Stevens, who designed the final patented design, believes the fluid-filled spectacles offer a range of benefits.

“There’s a benefit for retailers, with fewer stock keeping units on the shelf, and the consumer gets to choose what the consumer cares about – which is what [the spectacles] look like. We’re providing fundamentally better vision in any circumstance that they find themselves in,” Dr Stevens said.

"What is going to make someone walk into an opticians? Maybe they've got a new frame that you like, or maybe they have a new technology"

All of Adlens’ products have been through the medical device registration process in the countries and regions being sold, and safety, impact resistance and cytotoxicity tests, he explained. “And exceeded them.”

The company’s American distributor, Lens Crafters, also set a high bar for the Adlens products to meet before they would sell them, Dr Stevens said. “It had extremely stringent sets of requirements around what we were claiming we could do, the robustness of what we could do and the optical tolerances around what we could do.”

Dr Stevens said optometrists may want to view the technological development of Adlens’s fluid-filled lenses as a boost to business.

“What is going to make someone walk into an opticians? Maybe they’ve got a new frame that you like, or maybe they have a new technology that might be nice to talk about and provides some interest in an otherwise stagnant field, relatively speaking.”

Of all progressive lens wearers, around 6% cannot get used to the head motion they required, Dr Stevens emphasises. The fluid-filled lens, once adjusted by the dial, gives presbyopes a more natural way of looking at the world.

“We’re actually bringing a lot to offer [in eye health] – and I don’t think that’s coming across,” he highlighted.

Dr Mackenzie added: “We are at the forefront of a new lens technology – largest manufacturer, largest distributor, largest employer in this area in the world.”

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Image credit(s): Adlens