Efficacy of spherical aberration correction based on contact lens power

To investigate the efficacy of spherical aberration (SA) correction with aspheric contact lenses (aspheric lenses) based on lens power, and compare the results with those of spherical contact lenses (spherical lenses).

Ocular higher-order aberrations were measured with a wavefront sensor, in 11 myopic subjects wearing an aspheric lens (Medalist Fresh fit (PUREVISION 2 HD); Bausch+Lomb) or a spherical lens (ACUVUE Oasys; Johnson & Johnson). Six different lens powers (-7.00 diopters (D), -5.00 D, -3.00 D, -1.00 D, +1.00 D, +3.00 D) were used for all subjects. The amount of SA correction from the contact lens at each power was calculated as the difference between SA with the contact lens on-eye and SA of the eye alone.

For the spherical lenses, SA correction was close to 0.00 μm for the +1.00 D lens, became more positive as the labeled lens power increased and became more negative as the labeled lens power decreased. For the aspheric lenses, SA correction was consistent, from -0.15 to -0.05 μm, for all lens powers except for the -1.00 D lens. SA correction for the spherical and aspheric lenses was significantly different at -7.00 D (p=0.040), -3.00 D (p=0.015), -1.00 D (p<0.001), +1.00 D (p=0.006), and +3.00 D (p<0.001) powers.

An aspheric lens is capable of correcting SA at different lens powers, and has SA correction in the range of -0.15 to -0.05 μm over a 6mm aperture.