Power profiles of 3-addition multifocal soft contact lens system

Abstract

Significance: Simultaneous vision multifocal lens wearers face visual compromise from multiple optics covering the pupil. Modified monovision designs mitigate this by biasing eyes for distance/reading vision. Understanding designer-created bias from over/under correction, as presented in this paper with MyDay, helps practitioners assess contributions from refractive blur on wearer-reported visual symptoms.

Purpose: The aim of the study is to evaluate the in-vitro power profile of a new multifocal contact lens with 3 addition powers utilizing a modified monovision approach (MyDay multifocal, CooperVision) and compare it with other commercial multifocal lenses (Proclear and Clariti, CooperVision).

Methods: The in-vitro power profiles (n = 2 per power and add) were evaluated for +0.00 D, ±1.00 D, ±3.00 D, and ±5.00 D in low, medium, and high adds MyDay lenses, single add Proclear and high add Clariti using NIMO TR1504 (Lambda-X).

Results: Low and medium add MyDay showed similar and progressive radial power profiles with maximum plus power at the center with no distinct power zones (similar to Proclear). The average power change over 2.4 mm was +1.20 D for both adds but the medium add was offset by +0.50 D indicating overcorrection of the far point in nondominant eyes. High add MyDay showed three distinct annular power zones (similar to Clariti) with maximum plus in the central zone (2.0 mm) and stepped down across the annular zones (2 × 0.7 mm) to the peripheral (distance) zone (1.3 mm) by an average of +2.40 D over the 2.4 mm half-chord. High add MyDay showed significant power change across the peripheral (distance) zone both within a lens and across the labeled powers due to spherical aberrations.

Conclusions: MyDay multifocal 3-addition contact lenses have radial power profiles similar to Proclear lenses (MyDay low and medium adds) and Clariti high add lenses (MyDay high add). The uncorrected spherical aberration in the peripheral distance zone may result in patient fitting inconsistencies and increased visual disturbances.