Publications / Scientific Publications /

Correlation between Optical and Psychophysical Parameters as a Function of Defocus


Purpose. To evaluate how ocular optical image quality and psychophysical estimates of visual performance compare to each other as a function of defocus. Methods. We measured the optical modulation transfer function using a double-pass apparatus and psychophysical estimates of visual performance: contrast sensitivity function (CSF) and visual acuity. Both sets of data were obtained under the same optical conditions. Results. We measured optical and psychophysical parameters as a function of defocus. We studied the correlation between optical parameters (Strehl ratio and the logarithm of the volume in the double-pass image [log_Vol D-P]) and psychophysical parameters (the area under the fitted CSF represented in a logarithmic scale with the spatial frequency in linear scale [Area CSF-log_lin] and visual acuity) for different values of defocus. Conclusions. Strehl ratio is well correlated with the psychophysical estimates of the visual performance for moderate amount of defocus (within 1 D), whereas the other parameter (log_Vol D-P) is well correlated for larger ranges of defocus (within 2 D) and for different pupil diameters. These results suggest that optical measurements could be used for clinical testing of ophthalmic optics. (Optom Vis Sci 2002;79:

If you like it, please share it...Tweet about this on Twitter0Share on Facebook0