Does the Accommodative Mechanism of the Eye Calibrate ItselfUsing Aberration Dynamics?

摘要

Kotulak and Schor have suggested that the accommodative mechanism of thehuman eye can determine the required response from the changes in retinal im-age contrast associated with the microfluctuations of accommodation. As otheraberrations also display dynamic behaviour, they may too have an input in thisself-calibration mechanism. An adaptive optics system with separate measure-ment and manipulation channels was developed to investigate this possibility.A rotating diffuser is used to reduce laser speckle. The light hits the 37-elementpiezoelectric deformable mirror twice to increase its effective stroke. The accom-modation response to 0.75 D step changes in target vergence whilst invertingselective aberrations during the latency period was studied in three subjects.In two subjects, inversion of astigmatism and spherical aberration showed thegreatest effect; suggesting that for these subjects the eye potentially calibratesitself using information obtained from the aberration dynamics. One subjectcould not accommodate even with the aberrations left unchanged, and so mayrequire chromatic aberration to guide the accommodative mechanism.