Defocus vibrations in optical systems-considerations in reference to the human eye.

Experimental visual acuity (VA) of eight subjects was measured using the Freiburg vision test in a custom-made adaptive optics system. Measurements were conducted under one control and five defocus-induced conditions. In the defocus-induced conditions, 1 diopter of myopic defocus was added to the system using the Badal stage, and defocus vibrations with five different levels of amplitude were generated by a deformable mirror at 50 Hz. Computational simulations of the visual Strehl ratio (VSOTF) were performed using average aberrations of each subject recorded in the control condition. For the first time, to the best of our knowledge, it has been shown experimentally that both the simulated VSOTF and experimentally measured VA improve when defocus vibrations are added to a defocused eye.