Correlation between optical and psychophysical parameters as a function of defocus.
OBJECTIVE
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.
Villegas
Eloy A
EA
Laboratorio de Optica, Departamento de Física, Universidad de Murcia, Campus de Espinardo, Murcia, Spain. villegas@um.es
González
Concepción
C
Bourdoncle
Bernard
B
Bonnin
Thierry
T
Artal
Pablo
P
D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011601:Psychophysics; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*