However, the technological level for the development of adaptive optics systems in the 1950s was not yet high enough. The idea of using adaptive optics to compensate for distortions caused by low visibility was first proposed in 1953 by Horace Babcock, and the method of wavefront correction by a compound mirror was proposed and described by V.P. Among the advantages of the Shack-Hartmann sensor, one can distinguish an accuracy comparable to the interference method and achromaticity.Īdaptive methods are the most versatile tool for wavefront control and correction of optical aberrations over a wide range. When a focused beam leaves this region, errors in the measurement of slopes occur, leading to phase reconstruction errors. Local slopes can only be measured within the area assigned to the microlens. The finite dimensions of each of the sub-apertures lead to restrictions on the magnitude of the detected aberration. The Shack-Hartmann wavefront sensor is a device in which the wavefront is divided into separate beams by a matrix of focusing microlenses ( lens raster). This year, an algorithm for wavefront reconstruction was developed. A little later, a technology was developed to use aberrometric analysis for vision diagnostics. The idea of using wavefront technology belongs to J. Later it was modified in 1971 by Ronald Shack, and it is used in astronomy to compensate for aberrations in telescopes. It was first described in 1900 by Johann Hartmann.
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It covers the full size of the area to be studied with a certain step. Hartmann’s method, which appeared 100 years later, differs in that wavefront deviations are calculated from a set of sub-apertures. In addition, interferometers are able to determine the phase with an uncertainty of 2π, which imposes additional restrictions on the magnitude of detected aberrations. Disadvantages of interferometry are well known-they include the sensitivity of the measuring equipment to vibrations, as well as the need for the physical presence of a reference wavefront. In addition, taking into account the use of data mining and neural networks, the wavefront of a light field can be reconstructed from an interferogram with a reference beam of a given shape using both a diffractive and refractive optical element (in particular, a diffraction grating for forming a linear interferogram, a lens for spherical, axicon for conical). The accuracy of interferometers, especially heterodyne ones, exceeds λ/100. It still has unsurpassed accuracy and makes it possible to directly obtain a map of wavefront deviations at very large aperture sizes. This method was proposed as early as 1800 (Fizo, Jamin, Michelson, Jung). The results of numerical simulation showed that in order to improve the quality of the patient’s vision, it is necessary to take into account high-order aberrations of the anterior surface of the cornea in the form of a coma of the third order and aberrations of the fourth order.įor example, the wavefront of a light field can be reconstructed from an interferogram. We propose to compensate for the aberrations of the myopic eye, taking into account the physical features of the corneal surface. For an objective assessment of the quality of vision, the corresponding point spread functions (PSFs) were calculated. The original wavefront for the anterior and posterior surfaces of the cornea was restored separately, as well as the total wave aberration. Using data obtained by aberrometers, the average values of the Zernike polynomial coefficients for the anterior and posterior surfaces of the healthy eye cornea and a myopic one were calculated. The main part of the paper is devoted to the analysis of the weight coefficients of Zernike polynomials obtained during medical examinations of the cornea in the human eye. We shortly discuss the features (advantages and disadvantages) of various wavefront aberration sensors in the Introduction. Various diffractive, refractive and holographic optical elements, such as diffraction gratings microlens raster phase plates multi-order diffractive optical elements adaptive mirrors diffractive and refractive axicons holographic multiplexes and many others are used to analyze wavefront aberrations.
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