Peripheral optical quality of the eye with and without contact lens correction

Degraded peripheral vision has been hypothesized to be a stimulus for the development of refractive error. Since contact lenses have been widely used for refractive error correction, it is important to understand the effects of these lenses on peripheral vision. The purpose of my study was to investigate the changes in optical aberration across the horizontal visual field produced by contact lenses and to quantify the effect of contact lenses on peripheral image quality. I used a commercial Shack-Hartmann aberrometer to take measurement in 5° step out to 30° of eccentricity along the horizontal meridian in uncorrected eyes and in eyes corrected with soft contact lens (SCLs) or rigid gas permeable (RGP) contact lenses. Wavefront aberrations were obtained and analyzed based on the full elliptical pupil encountered in peripheral measurements. Commercial software (CLAS-2D) was used to deal with elliptical pupil problem. Aberration analysis over an elliptical pupil was verified with this method using a physical model eye. Both kinds of contact lenses reduce the amount of hyperopic field curvature but RGP lenses have the greater effect. Contact lens increases all higher-order aberrations in the peripheral visual field except 3rd-order Zernike terms. Compared to SCLs, RGP lenses improve peripheral image quality for objects located at the foveal far point. These results may help to explain why RGP lenses are more effective than SCLs in retarding myopia progression.