Abstract
Purpose: :
The effect of contact lenses on optical quality of the eye in the peripheral visual field is unknown. The purpose of our study was to evaluate peripheral wavefront aberrations and image quality across the visual field before and after contact lens correction.
Methods: :
A commercial Shack-Hartmann aberrometer was used to measure ocular wavefront errors in 5º steps out to 30º of eccentricity along the horizontal meridian in uncorrected eyes and when the same eyes are corrected with soft or rigid contact lenses. Wavefront aberrations and image quality were determined for the full elliptical pupil encountered in off-axis measurements.
Results: :
Ocular higher-order aberrations increase away from fovea in the uncorrected eye. Third-order aberrations are larger and increase faster with eccentricity compared to the other higher-order aberrations. Contact lenses increase all higher-order aberrations except 3rd-order Zernike terms. Nevertheless, a net increase in image quality across the horizontal visual field for objects located at the foveal far point is achieved with rigid lenses, whereas soft contact lenses reduce image quality.
Conclusions: :
Peripheral relative defocus and astigmatism are the most important aberrations limiting image quality in the peripheral field. These aberrations are reduced by contact lenses, but the corresponding gain in image quality is offset by increased amounts of higher-order aberrations. Improved designs of contact lenses would reduce the amount of higher-order aberrations induced by contact lenses while more accurately correcting the second-order aberrations of the peripheral field.
Keywords: aberrations • contact lens • myopia