Seven-years of the MiSight® 1 day study – Q&A with Dr Paul Chamberlain

This study was really designed to take a device from initial proof of concept stage to a device that becomes a validated product available to clinicians around the world. So, the learnings built up as the study went along. It’s pretty hard then to take one pivotal moment from what the study taught us in its entirety! Each phase of the 7-year study allowed us to chip away at the big unanswered questions: Would the treatment effect persist beyond one year? Beyond three years? Would it be safe and well accepted by children? The answer across all of these was consistently yes. 

 Rather than one defining moment, it was the strength of the entire body of evidence that mattered. This enabled the translation of MiSight® 1 day to a globally adopted, evidence-based myopia control option for children. 

The seven-year data help answer one of the big outstanding questions in long-term myopia management—what happens when treatment is stopped, and how to understand the so-called “rebound effect.” We set up the study deliberately to reflect clinical practice, so instead of taking children off treatment after only a year, we looked at what happened after three and six years of MiSight® 1 day wear. 

What we found was that in both groups, eye growth returned to normal, age-expected myopic growth rates once treatment was removed. The growth rate did speed up, but that wasn’t a surprise—without treatment, you wouldn’t expect the effect to continue.¹  This gave us the chance to clarify how rebound should be defined. An increase in eye growth after stopping treatment in progressing myopes is expected, and that does not necessarily mean rebound in the way some earlier papers implied. We wanted to give practitioners a clearer narrative on what rebound actually is—and isn’t—so they can interpret these changes confidently in clinical practice. 

The implications for management are important. For example, if a practitioner stops treatment at age 17 when a child heads off to university, and then notices progression speeding up, that tells us the treatment was removed too soon and can simply be reinstated. It highlights that myopia management is not about “graduating” from treatment at a certain age, but about ongoing clinical management tailored to the individual.

Introducing virtual control groups was critically important because our original control group had to be discontinued at the three-year mark. I stand by that decision—it was both ethical and practical. Extending the control group would have meant reconsenting families and asking parents to keep their children untreated for another three years, even after we knew MiSight®1 day was working. That would have been an unreasonable ask, and we would likely have lost the untreated population anyway. 

The virtual control group gave us a way to continue measuring long-term efficacy. Without it, we couldn’t have answered the crucial question of whether treatment remains worthwhile through the teenage years. We built these virtual controls by applying published growth models to our study population, and we validated the approach by comparing the model to our real control group from years one to three. The match was almost perfect, which gave us confidence that the model was applicable. With that validation, we were able to demonstrate six years of efficacy, showing practitioners that MiSight® 1 day can be effective throughout the progressing years of childhood and adolescence.²  The virtual control also allowed us to extrapolate to the year treatment was removed, confirming that efficacy wasn’t being lost due to a so-called rebound effect.

More broadly, this represents an evolution in how myopia control studies are conducted. As effective treatments become widely available, it’s increasingly difficult—and ethically questionable—to keep children in untreated control groups for many years. Virtual controls solve that dilemma, and we’ve already seen other research groups adopt similar models.

The MiSight® 1 day study really has been a catalyst in raising the global standard of care for myopia management. One of its most significant impacts was leading directly to the first regulatory approvals for a myopia control product. That was a landmark moment, because it meant practitioners finally had access to an approved device that had been through rigorous evaluation. Those approvals also helped pave the way for other products to follow, creating a more regulated and recognized landscape for myopia management— MiSight® 1 day’s recent approval in Japan is a good example of that progression.

Beyond approvals, the study has educated both practitioners and parents. The papers that came out of it have given eye care professionals the evidence and language to explain why myopia management matters, and why it’s worth doing. The study also introduced innovations like virtual control groups, which have since been adopted by others as a way to overcome the ethical and practical challenges of maintaining untreated control groups long term.

Just as importantly, the long-term data—particularly around efficacy, safety, and the so-called rebound effect—have addressed some of the concerns that made practitioners hesitant about prescribing. The evidence shows that treatment is effective and safe over many years, and that the benefits don’t simply vanish when treatment stops.

Altogether, the MiSight® 1 day study has set a new benchmark. It’s provided the sustained, long-term data the profession needed, justified current management strategies, and encouraged broader adoption and further innovation in myopia control globally.

In the near term, it’s all about accessibility. We want to make MiSight® 1 day optics available to more children by expanding the range of powers, addressing different types of myopia such as those with astigmatism, and incorporating the optics into the latest lens materials. The goal is to ensure that more myopes, who may not currently be candidates, can benefit from treatment.

 Looking further ahead, our priorities include improving efficacy, particularly for the faster progressors we saw in the MiSight® 1 day study who didn’t achieve what we’d consider a “perfect” outcome. We want to minimise poor outlier responses and strive for the strongest possible myopia-control effect—even exploring the question of whether we can reach “beyond non-growth.” A big part of that work involves understanding the mechanism of action more deeply: is it truly a stop signal we’re delivering, or are we eliminating a growth signal? That kind of fundamental research underpins everything we do.

 Finally, we’re continuing to learn from data—both from our original study and from new populations where MiSight® 1 day has been approved. For example, we’ve gained valuable insights from its performance in a Japanese population, which tends to progress faster. These comparisons help us refine our understanding and drive innovation forward.

For eye care professionals who are still hesitant about myopia management, the key takeaway from the MiSight® 1 day study is that there’s no longer a strong rationale for “waiting and seeing.” The data show very clearly that myopia management works, is safe, and can be integrated into children’s daily lives.

 We now have abundant evidence—not just from CooperVision—that interventions like contact lenses and spectacles provide effective myopia control for the vast majority of children, sustained over multiple years. The seven-year data also address one of the biggest concerns: the so-called rebound effect. What we saw was that when treatment is stopped, eye growth simply returns to normal, age-expected myopic growth rates. That means long-term efficacy and safety are maintained, and the effect doesn’t suddenly disappear. It reframes myopia management as an ongoing clinical process rather than a “graduation” from treatment at a certain age.

 In essence, this study offers a solid foundation for confidence. We now have long-term efficacy, long-term safety, and a clear understanding of what happens post-treatment. That should give every practitioner the reassurance they need to take an active role in myopia management rather than waiting on the sidelines.