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Objectives: This study aimed to investigate the influence of soft multifocal contact lenses with high additions designed for myopia control on binocular vision in young adults. Methods: A prospective randomized, double-blind study including 24 subjects aged between 18 and 36 years. Subjects were divided into two groups. The first group wore multifocal soft contact lenses (MFSCLs) with a 3.0 mm central zone diameter, while the second group wore contact lenses with 4.5 mm central zones. Each subject was fitted with two MFSCLs: one with +2.00 D and the other with +4.00 D peripheral addition power and, additionally, with plano single vision contact lenses (SVCLs). Phoria at a distance and near, distance and near vergence ranges, vergence facility at near, stereopsis at near, and fixation disparity at near were measured in each study lens type.Results: No significant influence of addition on distance phoria was found in either group (p = 0.446 and p = 0.317, for 3 mm and 4.5 mm central zone diameter, respectively). Additionally, no significant difference was observed for any MFSCLs and SVCLs in near phoria (p = 0.320), near vergence facility (p = 0.197), or near fixation disparity (p = 0.203). A decline in fusional vergence ranges at a distance in the base-out direction was noted in subjects wearing +4.00 D addition compared to +2.00 D addition (p = 0.002) and plano lenses (p = 0.014). Both additions reduced fusional vergence ranges at near the base out (p = 0.020) and shifted vergence ranges more in the exophoria base in directions (p = 0.014). Conclusions: The study showed that MFSCLs with high additional power in the periphery have only a marginal impact on the binocular functions.
Kropacz-Sobkowiak et al. (Sun,) studied this question.