This study showed that multi-zone spectacle and contact lenses used for myopia control provide myopic defocus at far distances. At near, changes in accommodative lag, pupil miosis and spherical aberration in individuals may mean there are lesser amounts of myopic defocus and reduced image quality. However, all the lenses were still able to provide sufficient image clarity at near for typical size print.
In young adult myopes, Biofinity centre-distance +2.50 Add and NaturalVue multifocal contact lenses both showed reduced visual acuity in lower lighting and low contrast conditions, and especially with a glare source, compared to single vision. Reading rate under normal lighting was also reduced by 4-8%. The multifocal designs performed similarly, although Biofinity required more over-refraction for best distance acuity.
This study showed that aspheric multifocal soft contact lenses (Biofinity +2.50D and NaturalVue) reduce accommodative response and increase exophoria, while MiSight concentric dual-focus minimally impacts binocular vision function compared to single vision contact lenses. All myopia control contact lenses increased divergence range slightly but did not impact convergence.
The MiSight 1 day clinical trial is the longest in soft lens myopia control, showing efficacy in children and teens in up to 6 years of wear. The first three years showed a 50-60% axial length and refractive efficacy. In the second three years, all control group children were switched to MiSight and showed axial growth similar to children under continued treatment, indicating benefits for commencing wear in children and teens alike.