A new approach to the study of ocular chromatic aberrations

Abstract

We measured the ocular wavefront aberration at six different visible wavelengths (between 450 and 650 nm) in three subjects, using a spatially resolved refractometer. In this technique, the angular deviation of light rays entering the pupil at different locations is measured with respect to a target viewed through a centered pupil. Fits of the data at each wavelength to Zernike polynomials were used to estimate the change of defocus with wavelength (longitudinal chromatic aberration, LCA) and the wavelength-dependence of the ocular aberrations. Measured LCA was in good agreement with the literature. In most cases the wavefront aberration increased slightly with wavelength. The angular deviations from the reference stimulus measured using a magenta filter allowed us to estimate the achromatic axis and both optical and perceived transverse chromatic aberration (TCA), (including the effect of aberrations and Stiles-Crawford effect). The amount of TCA varied markedly across subjects, and between eyes of the same subject. Finally, we used the results from these experiments to compute the image quality of the eye in polychromatic light.

Simultaneous quantification of longitudinal and transverse ocular chromatic aberrations with Hartmann–Shack wavefront sensor

“…12 In 1999, Marcos et al employed a spatially resolved refractometer to measure the LCA objectively in the visible range. The average LCA between 450 nm and 650 nm was 1.26 D. 13 In their study, unlike in most of the previous approaches based on subjective refraction, LCA was directly objectively estimated. LCA measurements gradually developed from using subjective methods to objective methods.…”

“…In 1999, Marcos et al used a spatially resolved refractometer to measure the di®erence between two alignments, which corresponded to TCAs in di®er-ent time moments; this method had a lower precision in the estimation of the foveal TCA (0.52-1.84 arcmin) between 473 nm and 601 nm. 13 The in°uence of the eye movements, in particular that of microsaccades, 26 was signi¯cant in the TCA measurement. In this method, each measurement had to be realigned to the reference, which was the main cause of the low precision.…”

Experimentally observe the effect of spherical aberration on diffractive intraocular lens using adaptive optics

“…Considering that the eye's SA should be independent on the visible wavelength especially in a small pupil size, 20 the chromatic SA is assumed to be small. However, longitudinal chromatic defocus, although possibly reducible by proper materials of the IOL, 21 can systematically degrade the image quality at both foci of a DIOL.…”

The Optical Design of the Human Eye: a Critical Review

“…85 LCA shows low intersubject variability and good agreement between model predictions and experimental data. 7,8 On the contrary, TCA varies among subjects 86,87 and is hardly predicted by rotationally symmetric eye models.…”