Varilux® X seriesTM: the 8th generation of the Varilux® progressive lens
The Varilux® progressive lens has been through a great variety of innovations since it was first introduced by Bernard Maitenaz in 1959. Seven generations have already come and gone, and each one – from Varilux® 2 (1973) to Varilux® Comfort (1993), Varilux® Panamic® (2000), Varilux® Physio® (2006) and the Varilux® S seriesTM (2012) – brought improvements that reflected the accumulated experience of previous years. While this is not the place to describe each of those generations in detail (for that you can refer to the various publications that accompanied each one), it is undeniably true that the Varilux® lens has always been at the cutting edge of innovation and represents the standard against which other lenses are measured. The 8th generation is no exception and introduces two major innovations: an expanded field of near vision that includes “arm’s-length” vision, and the ability to customize the lens progression based on the wearer’s near-vision behaviour. These innovations have been described in detail in two white papers [2, 3] published by Essilor’s Research & Development department and summarized in two recently published articles [4, 5].
From the research lab to the market, wearers are the centre of attention
“The wearer is always right!” – that’s the motto of Essilor’s Research & Development team, which has been focusing its attention on wearers for decades. In everything from special studies designed to generate new concepts to our testing of prototype lenses, when they’re used as representative samples of the target population, wearers play an integral role in the research process from start to finish. That process, known as the “Dioptric Loop” in the 1990s and as “Live Optics” since 2010, is based on the idea that only wearers can assess the level of progress in lenses, and that research must be conducted with the aim of ensuring enhanced vision and greater satisfaction among wearers. Wearers are used in studies because ultimately they are the best representatives of the patients examined by ophthalmologists and optometrists and the customers fitted with lenses by opticians.
As a result, Essilor has been conducting two types of testing over the past few decades: so-called «wearer studies», performed in accordance with controlled scientific protocols in laboratory or real-life conditions, and «market testing», conducted under actual market conditions.The purpose of wearer studies is to validate improvements to lenses on wearers, while market testing is designed to confirm that customers actually perceive the benefits provided by the new lenses.
For the Varilux® X seriesTM lens, the “Live Optics” model has been enhanced so as to yield an even better understanding of wearers and to verify that this latest innovation truly addresses the vision needs of patients with presbyopia.
Those enhancements initially related to the lens design phase. Designers began focusing on emerging needs among wearers, especially posture concerns and new practices prompted by a changing society. These include the use of smartphones or tablets or both, with users routinely switching from one to the other – new activities that are generally conducted at arm’s-length distance.
Second, researchers drew on new tools and methodologies to improve their understanding of wearer behavior and wearers’ expectations. For example, they placed wearers into an experimental laboratory (the Movis LabTM, see Figure 1), where their movements could be measured and their position analysed in real time and 3D. Moreover, wearers were asked to make video selfies showing the most problematic vision situations they encountered with their progressive lenses, so researchers could learn more about their day-to-day needs.
Fig. 1 : Movis Lab™
During the third stage of the research, in order to assess the performance of the Varilux® X seriesTM lenses, wearers wore them in real-life conditions during three types of tests. Comparative “wearer studies” were conducted on representative samples of wearers; those studies were supplemented by a new kind of “usage study” in which patients wearing Varilux® X seriesTM performed routine tasks in a familiar environment (the HouseLabTM; see Figure 2). Lastly, a large-scale “market test” was conducted prior to introduce the lens on the market, to confirm that wearers truly perceived the new lens’s advantages under actual market conditions.
Fig. 2: Some examples of activities performed and measured in the HouseLab™
The following chapters briefly summarize the results of the studies conducted for this new lens.
Varilux® X seriesTM lenses: performance and benefits borne out by wearers
Before to begin the development and deployment phase of a new progressive lens, the lens concept is tested under real-life conditions in accordance with a rigorous scientific protocol. The Varilux® X seriesTM lens was subjected to this testing just as all its predecessors were. Several studies were conducted to confirm the effectiveness of the Varilux® X design (non-personalized version), validate the benefits for wearers under key use conditions and demonstrate the value of the Varilux® X seriesTM “NVB” (Near Vision Behaviour personalization).
a) The Varilux® X design was perceived as superior to the Varilux® S® design
An international multi-centre study was conducted under real-life conditions, in accordance with the study protocol used by Essilor (validated by an independent body*). This comparative study was randomized and double-blind; in other words, neither the investigator nor the wearer knew the exact nature of the lenses tested, and the lenses that were worn were issued on a random basis.
Wearers were first given a market lens for their new prescription, to wear for at least three weeks during a special preliminary period called the “wash-out” period; they then wore a test lens and a reference lens for two successive periods of two weeks each.
All three pairs of eyeglasses were identical in every other respect (the same frames, material, coatings, powers and centering), so as to isolate the parameters that were specific to each design tested.
The study consisted of comparing the new Varilux® X design, without the “Near Vision Behaviour” option, with the Varilux® S® design lens from the previous-generation Varilux® S® series, which is the market reference. The wearers wore the two lenses in succession, then were interviewed and asked to fill out detailed, standardized questionnaires, in order to gather their assessments of the lenses.
The results we obtained, which are shown in Figure 3, are worth studying. We find that among the group of 66 wearers who took part in the study (Figure 3a):
- Quality of vision with the Varilux® X design was rated superior to that of the Varilux® S® design on every criterion (Figure 3b).
- 65% of the wearers who expressed a preference chose the Varilux® X design lens (Figure 3c).
- 82% of the wearers said that adapting to the Varilux® X design was “easy” or “very easy”, versus 76% for the Varilux® S® design (Figure 3d).
- The wearers readily indicated that they were highly satisfied with the lens, as some of their comments make clear (Figure 3e).
These results indicate the degree to which wearers enjoy the new Varilux® X design lens and the marked improvements it provides over the previous generation of lenses.
Fig. 3: Comparison of the Varilux® X design and Varilux® S® design lens among wearers - International multicenter study (n=66)
b) The Varilux® X design lens: proven benefits for “arm’s-length vision”
In addition to the comparison with the Varilux® S® design lens, the quality of arm’s-length vision available with the Varilux® X design was investigated as well, with a specific study of 42 wearers in France (Figure 4a). During that study, wearers who normally use Varilux® S® design lenses were placed in a controlled home environment known as the HouseLab™. In that routine setting, they were asked to perform activities conducted at arm’s length, using the Varilux® X design lenses. The tasks in question were chosen because they are typical of the activities that wearers of progressive lenses find difficult.
The results of that study, shown in Figure 4b, bear out the high opinion of the lenses among wearers, regardless of whether they were asked to perform near-vision or mid-distance-vision tasks. That result was corroborated by the fact that 97% of wearers reported having to make “few” or “no” horizontal head movements, and 93% of wearers reported “few” or “no” vertical head movements, to explore their near-vision space (Figure 4c). That latter figure represents a major advance, since the vertical head movements that progressive lenses require for near and mid-distance vision are often a source of complaint among wearers. So these results confirm the new benefit offered by the Varilux® X design lens.
Thus, the design performance of the new Varilux® X design lens was largely borne out.
Fig. 4: Evaluation of «arm’s-length vision» with the Varilux® X design lens - Single-center study - Eurosyn - France (n=42)
c) The personnalized “NVB” version of the Varilux® X design lens was found to be superior to the Varilux® X design standard lens
Once the performance of the new Varilux® X design had been established, there remained the task of confirming and demonstrating the benefits of the new personalized Varilux® X seriesTM “NVB”. As a reminder, that option involves measuring each wearer’s near-vision posture and behaviour and designing, calculating and manufacturing a progressive lens that reflects those customized parameters. The principle behind the NVB feature was described in detail in a previous article5.
For that purpose, another comparative wearer study was conducted in accordance with the same strict protocol described above. This study was conducted simultaneously at several research centres with a sample population of 51 wearers (Figure 5a).
The study’s results can be summarized as follows:
- Vision quality with the Varilux® X seriesTM “NVB” lens was rated high or very high on every criterion by a very large majority of wearers (Figure 5b).
- 62% of the wearers who expressed a preference chose the Varilux® X seriesTM “NVB” lens (Figure 5c).
- 90% of the wearers said that adapting to the Varilux® X seriesTM “NVB” lens was “easy” or “very easy” (Figure 5d)
Fig. 5: Evaluation and comparison of the Varilux® X seriesTM «NVB» and the Varilux® X design lens among wearers - International multicenter study (n=51)
d) Varilux® X seriesTM: the benefits are perceived by customers under actual market conditions
Having demonstrated the performance of the Varilux® X seriesTM lens in both the non-personalized and the personalized versions during controlled, protocol-based studies, it was needed to know how the lens was perceived by wearers under real-life market conditions. Therefore, a wide-ranging market test was conducted across Europe, with more than 200 wearers recruited in 22 countries (Figure 6a). Nearly all of the participants (about 93%) were already wearers of progressive lenses and received their new Varilux® X design lenses under typical prescription and adaptation conditions, without any specific protocol. They wore their new lenses for a nominal period of at least two weeks, and then completed an evaluation questionnaire that had previously been translated into their language.
A summary of the results from the 172 completed questionnaires received is shown in Figure 6. In particular, we see that:
- Wearers expressed a very high level of both general satisfaction (above 94%) and satisfaction with quality of vision (95%) (Figure 6b). These levels are similar to those expressed under controlled protocol-based study conditions.
- Adaptation was considered “easy” or “very easy” by 82% of the wearers – “less than one day”, according to 87%. It is worth remembering that a new progressive lens always requires a learning period (Figure 6c), and that wearers should always be notified of that beforehand.
- The level of satisfaction during activities that require arm’s-length vision also proved quite high: up to 95% of wearers declared they were “satisfied” or “very satisfied” with their lenses for the multiple activities performed at that distance (Figure 6d).
- It’s important to note that at least 73% of the wearers surveyed said they were “more satisfied” with their new lenses than with their previous ones, both for general use and for tasks performed at arm’s length.
- Lastly, one especially notable point is that a large majority of wearers – 92% – reported having to make “few” or “no” horizontal head movements for clear arm’s-length vision, and 94% of wearers reported “few” or “no” vertical head movements (Figure 6e). This finding deserves special emphasis, since it conveys the specific advantage provided by the Varilux® X design lens.
Fig. 6: Evaluation of Varilux® X design lens among wearers in European market testing (n=172)
These results, obtained under actual market conditions, confirm those of earlier studies and show the extent to which the benefits found by wearers under controlled, protocol-based study conditions are also observed by clients in daily professional practice.
Moreover, those results were obtained with the non-personalized version of the lens; in other words, they show that the Varilux® X design lens is an excellent product. This suggests an even higher level of performance with the personalized “NVB” version.
Having new lenses tested by wearers is the only way to ensure that they perform effectively and it also helps to ensure their success. Essilor continues to invest a great deal of means and energy in wearer testing, in order to validate and confirm the efficacy of a new lens before introducing it on the market.
Like its predecessors, the Varilux® X seriesTM lens was subjected to an evaluation by wearers, both during its design phase and before being introduced on the market. As a result, Essilor was able to show that wearers enjoy the high quality of the lens even in its non-personalized version, Varilux® X design ; in particular, they see how it represents a major innovation with regard to arm’s-length vision. Moreover, with the Varilux® X seriesTM “NVB” lens that is personalized to the wearer’s near-vision behaviour, the product ushers in a new era of sophisticated progressive lenses that wearers will especially appreciate. Whether those wearers are patients or clients, they represent the consumers of tomorrow. We hope Eye Care Professionals will be able to capitalize on this new innovation to provide new generations of presbyopes with even greater visual comfort. •