Browsing by Subject "Chromatic aberration"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Open Access
    Adaptation to the eye’s chromatic aberration measured with an adaptive optics visual simulator
    (Optica Publishing Group, 2020) Fernandez, Enrique J.; Suchkov, Nikolai; Artal, Pablo; Fernandez, Enrique J.; Física
    Some aspects of vision after correcting the longitudinal chromatic aberration (LCA) of the eye are not yet completely understood. For instance, correcting the LCA notably alters the through focus visual acuity (VA) curve, but it does not improve the best VA obtained for the natural case. In this work, vision with corrected LCA is further investigated by using an adaptive optics visual simulator (AOVS). VA was measured continuously during 20 minutes in 5 subjects under both natural and corrected LCA conditions to explore possible adaptation effects. Low contrast VA as a function of time exhibited a consistent and significant boost of 0.19 in decimal scale after an average time of 10.9 minutes of continuous testing. For high contrast, only one subject showed a similar increase in VA. These results suggest that some LCA neural adaptation may exist, particularly for low contrast. This adaptation impacts the performance of vision under corrected LCA, and possibly prevents measurement for immediate visual benefit. The results have practical implications for the design and visual testing of optical aids, especially those correcting, or altering, the LCA.
  • Thumbnail Image
    Publication
    Open Access
    Impact of longitudinal chromatic aberration on through-focus visual acuity
    (Optica Publishing Group, 2019) Suchkov, Nikolai; Fernandez, Enrique J.; Artal, Pablo; Fernandez, Enrique J.; Física
    An enhanced adaptive optics visual simulator (AOVS) was used to study the impact of chromatic aberration on vision. In particular, through-focus visual acuity (VA) was measured in four subjects under three longitudinal chromatic aberration (LCA) conditions: natural LCA, compensated LCA and doubled LCA. Ray-tracing simulations using a chromatic eye model were also performed for a better understanding of experimental results. Simulations predicted the optical quality of the retinal images and VA by applying a semi-empirical formula. Experimental and ray tracing results showed a significant agreement in the natural LCA case (R2 = 0.92). Modifying the LCA caused an impairment in the predictability of the results, with decreasing correlations between experiment and simulations (compensated LCA, R2 = 0.84; doubled LCA, R2 = 0.59). VA under modified LCA was systematically overestimated by the model around the best focus position. The results provided useful information on how LCA manipulation affects the depth of focus. Decreased capability of the model to predict VA in modified LCA conditions suggests that neural adaptation may play a role.