title: Uniformity of accommodation across the visual field.
abstract: We asked the question: Does accommodation change the eye's focusing power equally over the central visual field in emmetropic and myopic adult eyes? To answer this question we modified our laboratory scanning wavefront aberrometer to rapidly measure ocular refractive state over the central 30° diameter of visual field as a function of foveal accommodative demand. On average, ocular refractive state changed uniformly over the central visual field as the eye accommodated up to 6 D. Visual field maps of accommodative error (relative to a spherical target surface of constant vergence) reveal subtle patterns of deviation on the order of ± 0.5 D that are unique to the individual and relatively invariant to changes in accommodative state. Population mean maps for accommodative error are remarkably uniform across the central visual field, indicating the retina of the hypothetical "average eye" is conjugate to a sphere of constant target vergence for all states of accommodation, even though individual eyes might deviate from the mean due to random variations. No systematic difference between emmetropic and myopic eyes was evident. Since accuracy of accommodation across the central visual field is similar to that measured in the fovea, loss of image quality due to accommodative errors, which potentially drives myopia and may affect many aspects of visual function, will be similar across the central retina.
authors: Tao
authors: T
authors: Liu
authors: Vidhyapriya
authors: V
authors: Sreenivasan
authors: Larry N
authors: LN
authors: Thibos
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D058453:Emmetropia / Q000502:physiology*; D006801:Humans; D009216:Myopia / Q000503:physiopathology*; D012029:Refraction, Ocular / Q000502:physiology; D014785:Vision, Ocular; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult