Abstract
PURPOSE: To measure the effect of the correction of the natural ocular aberrations on the subject's performance in four visual tasks.
METHODS: A psychophysics channel was inserted in a custom adaptive-optics (AO) system provided with a deformable-mirror and a Hartmann-Shack sensor (Imagine Eyes). VA was measured with tumbling black E-letters. For subjective quality preference we presented 34 natural images viewed alternatively by the subject through natural aberrations/AO correction, to choose the “sharpest”. For face recognition we presented 33 faces (15 familiar), randomly with/without AO-correction. The task required identifying familiar faces (1–6 score). The fourth experiment was similar, the task being to recognize facial expressions (39 happy/angry). Results of quality preference were analysed in terms of percentage images preferred with/without AO; recognition as the area under Response-Operating-Curves (Au_ROC). Measurements were done on three young subjects.
RESULTS: 1) Responses varied across subjects depending on the corrected aberrations. S1 showed the lowest amount of natural aberrations, the lowest AO correction, a VA decrease with correction (x0.96) and preferred 94% of images viewed with natural aberrations; S3 experienced the highest AO-correction, the largest VA benefit (x1.17) and preferred 97% of the images under correction. 2) For familiar face recognition, the Au_ROC curves increased by x1.13 (average) with correction. 3) For facial expression recognition, no subject benefited from correction (Au_ROC changed by x0.82).
CONCLUSION: Correcting ocular aberrations produces improvement in VA, subjective sharpness impression and face recognition in subjects with significant AO-correction. Facial expression recognition does not benefit from correction. Neural adaptation effects cannot be discarded.
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