Off-Axis Ocular Monochromatic Aberrations Estimated From Double Pass Measurements

Although ocular aberrations increase largely for objects located off-axis, the peripheral image quality has been relatively ignored in comparison with the widely studied foveal optical performance. Previous work has been concentrated in the off-axis refraction and oblique astigmatism (1-3), and the overall image quality expressed through the modulation transfer function (MTF) obtained with the double pass method as a function of the retinal eccentricity (4-6). In this study, we perform an analysis of the monochromatic aberrations that affects the retinal images in the periphery. This extends previous works, where the use of conventional versions of the double pass apparatus failed to obtain information on the off-axis asymmetric aberrations, mainly coma. The results show the relative contribution of the main aberrations we found off-axis: defocus, astigmatism and coma.