June 16, 2025
By Ashley Tucker, OD, FAAO, FSLS, ABO Diplomate
Photo Credit: Getty Images
The study, “Accommodating behaviour and retinal defocus in highly myopic eyes fitted with a dual focus myopia control contact lens” by Meyer et al. (2025), investigated how dual focus (DF) myopia control contact lenses affect accommodative behavior and retinal defocus in individuals with high myopia. High myopia is defined as spherical equivalent refractive error (SERE) between -6.50D and -9.25D.
For the study, 13 subjects (ages 13-32 years old) were fitted bilaterally with both a Proclear 1 day (omafilcon A, CooperVision, Inc.) single vision (SV) lens and a custom dual-focus (DF) lens. The DF lens matched the power profile and zone geometry of the commercially available MiSight 1 day (omafilcon A, CooperVision, Inc.), since the higher lens powers are not commercially available.
Testing the Lenses
Wavefront measurements were obtained using a pyramidal aberrometer (Osiris, CSO) aligned to the participant’s right eye along the primary line of sight, as well as across the central ±20° of the horizontal retina. Measurements were conducted under binocular viewing conditions while participants fixated on high-contrast dynamic letter stimuli (equivalent to 6/12 or 0.30 logMAR) presented at six target vergences: −0.25D and −1.00D to −5.00D in 1.00D increments. The fixation targets were scaled appropriately for each viewing distance and positioned either centrally or at ±10° and ±20° eccentricities along the horizontal meridian. Custom MATLAB software processed the exported wavefront data to compute local refractive states and retinal defocus. Linear mixed-effects (LME) regression models were employed to assess the influence of SERE, target vergence, and eccentricity on retinal defocus outcomes, accounting for repeated measures within subjects.
The DF lens produced the intended retinal defocus of approximately −2.00D, with a measured mean difference of −2.21D ± 0.18D compared to SV correction in the inner treatment ring. Accommodative accuracy was not significantly affected by the DF lens. However, accommodative lag increased at closer viewing distances, rising by approximately 0.30D for every additional diopter of myopia. Retinal defocus in the annular treatment zone remained close to −2.00D across the central retina, 10° nasal and temporal and 20° nasal, tapering slightly to −1.90D ± 0.57D at 20° temporal.
Conclusion
The anatomical and functional differences in highly myopic eyes reduce the amount of intended myopic retinal defocus delivered by the DF lens. This could potentially limit its efficacy in this population. Despite this attenuation, the specialized treatment zones of the DF lens still exert a beneficial optical effect. This occurs by simultaneously reducing hyperopic defocus—commonly associated with myopia progression—and introducing relative myopic defocus when compared to conventional SV lens correction.
These findings suggest that while DF lenses remain beneficial in highly myopic individuals, their optical impact may be moderated by the unique biomechanical and optical properties of more advanced myopic eyes.
ABSTRACT
Accommodative Behavior and Retinal Defocus in Highly Myopic Eyes Fitted With a Dual-Focus Myopia Control Contact Lens
Dawn Meyer , Javier Gantes-Nuñez, Martin Rickert, Nitya Murthy, Paul Chamberlain, Arthur Bradley, Pete Kollbaum
Purpose
To evaluate the myopic and hyperopic defocus delivered to the retina by a dual focus (DF) myopia control contact lens when myopia exceeds 6.00 D.
Methods
Individuals with high myopia were fitted bilaterally with high-powered DF lenses containing power profiles matching a Coopervision MiSight 1 day contact lens (omafilcon A) and a Coopervision Proclear 1 day single vision (SV) lens. Wavefront measurements along the primary line of sight and across the central ±20° of the horizontal retina were acquired using a pyramidal aberrometer, while subjects accommodated to high-contrast letter stimuli (6/12 equivalent) at six target vergences (-0.25 and -1.00 to -5.00 D). Linear mixed-effects regression models explored the relationship between the spherical equivalent refractive error (SERE) and induced defocus.
Results
Thirteen teenagers and young adults (ages 13-32 years, mean [standard deviation, SD] age = 22.8 [4.9] years) with high myopia (SERE -6.50 to -9.25 D) were tested. The treatment optic zone of the DF lens shifted retinal defocus by the expected -2.00 D, with a mean (SD) difference (DF-SV) of -2.21 (0.18) D for the inner treatment ring. Inclusion of the treatment optic had no significant impact on accommodative accuracy (p = 0.51). Accommodative lags were larger at the nearer viewing distances, with lag increasing by approximately 0.30 D for every additional dioptre of SERE. Measured retinal defocus within the annular treatment zone was approximately -2.00 D at the foveal centre, 10° nasal and temporal and 20° nasal and reduced to -1.90 (0.57) D at 20° temporal.
Conclusions
Relative to eyes with lower levels of myopia, the increased accommodative lags and more prolate retinas of highly myopic eyes reduced the myopic retinal defocus from the DF myopia control lens, while the treatment optical zones generated the combined effect of reducing hyperopic and introducing myopic retinal defocus relative to an SV correction.
DOI: 10.1111/opo.13420
