Adaptive Optics to Test Adaptation to the Eye's Optics

Visual perception is constantly calibrated by adaptation processes that can alter the appearance of color [1] and the perception of blur in natural scenes. In brief, how the world looks depends on the recent visual experience. The perceived focus of an image can be strongly biased by prior adaptation to a blurred or sharpened image [2]. The images projected on the retina are degraded by the optical aberrations of the eye. While low order aberrations (defocus and astigmatism) are normally corrected with spectacles or contact lenses, High Order Aberrations (HOA) (i. e. coma or spherical aberration) remain uncorrected, leaving the visual system chronically exposed to optically blurred images. One of the ultimate questions in visual optics is how these ocular aberrations affect visual performance and how vision can adapt to different patterns of ocular aberrations. Some studies have suggested that the eye can adapt to the increased HOA produced by corneal pathologies [3] or refractive surgery [4] and that both shortand long-term adaptation to orientation of blur can occur [5-7]. We used an Adaptive-Optics system to measure and correct all observers’ aberrations, allowing to control the blur level of the retinal image and test directly neural adaptation to the eye’s optics (fig1A). In a serie of psychophysical experiments, we explored whether visual coding is matched to the optical quality specific to the observer’s eye: do individuals neurally compensate for the blur produced by their own aberrations? Does their perception of best-focused image change after adapting to another individual’s retinal blur? Are they adapted to their overall amount of blur, or to specific blur features?