Researchers recently discovered fitting young adults with multifocal contact lenses (MFCLs) for myopia control could affect the eyes’ accommodative behavior, leading to less than optimal retinal image quality. The small study looked at eight patients around the age of 27 who were fit with center-near and center-distance MFCLs. After testing monocular and binocular vision with single vision and with both contact lens designs, the researchers noted the complexity of vision in the modality.
Beyond the far point of the near add, the subjects used the added plus power to help focus near targets, creating reduced accommodative gain. In addition, paraxial images were always hyperopically or myopically defocused when the participants were viewing binocularly with the center-distance or center-near designs, respectively.
“These results reveal that young accommodating adults fit with multifocal contact lenses do take advantage of the lens add powers to reduce their accommodative responses,” the researchers said. And while “young accommodating subjects viewing binocularly through center-distance and center-near multifocal contact lenses with significant transitions zones generally do not focus either the pupil center or pupil margins,” they also noted some limitations of the study: “because of the limited sample size (eight subjects), it would be inappropriate to assert that the sample means are representative of the broader patient population.”
|Altoaimi BH, Almutairi MS, Kollbaum PS, Bradley A. Accommodative behavior of young eyes wearing multifocal contact lenses. Optom Vis Sci. 2018;95(5):416-27.|