Power Profiles of Commercial Multifocal Soft Contact Lenses

Abstract

Purpose: To evaluate the optical power profiles of commercially available soft multifocal contact lenses and compare their optical designs.

Methods: The power profiles of 38 types of multifocal contact lenses-three lenses each-were measured in powers +6D, +3D, +1D, -1D, -3D, and -6D using NIMO TR1504 (Lambda-X, Belgium). All lenses were measured in phosphate buffered saline across 8 mm optic zone diameter. Refractive index of each lens material was measured using CLR 12-70 (Index Instruments, UK), which was used for converting measured power in the medium to in-air radial power profiles.

Results: Three basic types of power profiles were identified: center-near, center-distance, and concentric-zone ring-type designs. For most of the lens types, the relative plus with respect to prescription power was lower than the corresponding spectacle add. For some lens types, the measured power profiles were shifted by up to 1D across the power range relative to their labeled power. Most of the lenses were designed with noticeable amounts of spherical aberration. The sign and magnitude of spherical aberration can either be power dependent or consistent across the power range.

Conclusions: Power profiles can vary widely between the different lens types; however, certain similarities were also observed between some of the center-near designs. For the more recently released lens types, there seems to be a trend emerging to reduce the relative plus with respect to prescription power, include negative spherical aberration, and keep the power profiles consistent across the power range.

FIGURE 1

CLOQA image of ACUVUE OASYS for PRESBYOPIA Hi Add Power −1.00D (A), Clariti 1 day Hi Add Power −3.00D lens (B), PureVision2 for Presbyopia Hi Add Power +1.00D lens (C), ACUVUE OASYS for PRESBYOPIA Mid Add Power −6.00D lens (D), Proclear multifocal center-near 1.00 Add Power −6.00D lens (E), AIR OPTIX AQUA High Add Power +1.00D lens (F).

FIGURE 2

Absolute refractive power profiles of Proclear and Biofinity multifocal contact lenses—in four different addition powers. The measurements for central 0.5 mm are unreliable and hence were ignored in all graphs.

FIGURE 3

Absolute refractive power profiles of ACUVUE OASYS for PRESBYOPIA, 1-DAY ACUVUE MOIST, AIR OPTIX AQUA, and DAILIES Aqua Comfort Plus and multifocal contact lenses—in three different addition powers.

FIGURE 4

Absolute refractive power profiles of PureVision2 for Presbyopia, SofLens, Biotrue ONEday for Presbyopia, and Clariti 1 day multifocal contact lenses—in two different addition powers.

FIGURE 5

Absolute refractive power profiles of FOCUS DAILIES Progressives and Proclear 1 day multifocal contact lenses—in single progressive addition power.

FIGURE 6

Relative refractive power profiles of all −3.00D multifocal lenses.

FIGURE 7

Multifocal contact lenses where spherical aberration is uniform as a function of power.

FIGURE 7

Multifocal contact lenses where spherical aberration is uniform as a function of power.

FIGURE 8

Multifocal contact lenses where spherical aberration is not uniform as a function of power; center-near designs.

FIGURE 8

Multifocal contact lenses where spherical aberration is not uniform as a function of power; center-near designs.

FIGURE 9

Multifocal contact lenses where spherical aberration is not uniform as a function of power; center-distance designs.