Double-pass wave model in eye aberrations study

Autor: Vitalij N. Kurashov, Tetiana V. Molebna, Dmitrij V. Podanchuk, Vasyl V. Molebny, Andry V. Kovalenko, Ioannis G. Pallikaris, Leonidas P. Naoumidis
Rok vydání: 1997
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.297847
Popis: A modified double-pass wave model is proposed being a wave diffraction model of the secondary coherent field formed due to double pass of light in the human eye system. The modification takes into account: cornea contribution into total eye refraction, coherent nature of light reflection from the retina, and non-additive character of the cornea and lens aberrations. Irreversibility and anisoplanatism of the optical eye system follow from this study concurrently with the fact that the coherent point-spread function of double pass is not the autocorrelation of single-pass point- spread function. We used Hartmann-Shack wave front sensor and found it to be a promising technique for eye aberrations study: refraction map of the whole eye aperture can be reconstructed from a single-pulse information, presenting essential advantage as compared with point-by-point measurements. TV image of spot pairs can be got with CCD camera, its lens being replaced with lenslet array. Image processing consists in distance calculation between corresponding spot pairs. We use two-pulse exposure for this purpose: one--for producing a reference set of spots, the second one--for getting the spots produced by a distorted wave front. The sensitivity of this technique is estimated to be of the order of several percents.
Databáze: OpenAIRE