Development of a human eye model incorporated with intraocular scattering for visual performance assessment

Abstract

Abstract. A biometry-based human eye model was developed by using the empirical anatomic and optical data of ocular parameters. The gradient refractive index of the crystalline lens was modeled by concentric conicoid isoindical surfaces and was adaptive to accommodation and age. The chromatic dispersion of ocular media was described by Cauchy equations. The intraocular scattering model was composed of volumetric Mie scattering in the cornea and the crystalline lens, and a diffusive-surface model at the retina fundus. The retina was regarded as a Lambertian surface and was assigned its corresponding reflectance at each wavelength. The optical performance of the eye model was evaluated in CodeV and ASAP and presented by the modulation transfer functions at single and multiple wavelengths. The chromatic optical powers obtained from this model resembled that of the average physiological eyes. The scattering property was assessed by means of glare veiling luminance and compared with the CIE general disability glare equation. By replacing the transparent lens with a cataractous lens, the disability glare curve of cataracts was generated to compare with the normal disability glare curve. This model has high potential for investigating visual performance in ordinary lighting and display conditions and under the influence of glare sources.

Accommodation and age-dependent eye model based on in vivo measurements

“…Thus later authors4, 5 developed new, simplified, eye models to make calculations easier to perform. In contrast, with the availability of computers to speed calculation, other more recent models have often included additional characteristics in order to achieve a better approximation to real eyes, such as: aspheric surfaces6, 7, 8, 9, 10, 11, 12; chromatic dispersion6, 9, 12; intraocular scattering 13 ; changes with accommodation3, 4, 6, 9, 11, 12, 14; and age 7, 11, 15, 16. In the last few years, information produced by new devices capable of taking numerous “ in vivo” clinical measurements of the optical parameters of real eyes has been used by some authors to develop further eye models based on statistical data for the ocular parameters 11, 12, 17, 18, 19…”

Ray tracing 3D spectral scenes through human optics models

“…In this approach, users can specify materials with custom attenuation and scattering coefficients over wavelength, as well as modify the phase function, which determines the angle of scattering. One method of implementing intraocular scattering models (Chen, Jiang, Yang, & Sun, 2012) would be to find coefficients and phase functions that approximate the scattering models for the cornea and lens. We would then implement participating media within the lens-tracing portion of the simulation and associate each ocular media with their specific scattering parameters.…”

Light scattering in the human eye modelled as random phase perturbations

“…Van den Berg et al [ 2 ] simplified the intraocular scattering sources to micro spheres analyzing forward light distribution from donor lenses. Under the same simplification, Chen et al [ 3 ] introduced a biometry-based model with intraocular scattering. In this model, the spheres were located at the cornea and their size and concentration were optimized for adjusting the PSF to a glare equation suggested by the CIE (Commission International d’Eclairage) [ 4 ].…”