Development of an Algorithm using Zernike Polynomials and Fourier Transform for Measuring Refractive Errors in the Human Eyes
Authors: Marie Cattleah D. Atas, Larish Mariam T. Landicho, Abigail D. Lobo, Carla Joy L. Orubia, Adolph Christian O. Silverio, John Carlo V. Puno
Abstract
This study aims to develop an algorithm using Zernike polynomials and Fourier transform to provide a reliable measurement of refractive errors that will aid ophthalmologists and optometrists. A Shack-Hartmann wavefront sensor captures the wavefront of the eyes and provides the raw image that will be processed. The Fast Fourier Transform (FFT) of the image is computed and the magnitude and phase spectrum from two peaks surrounding the DC frequency are generated. These values are correlated and computations using formula for Zernike polynomials are performed. The outputs are spherical (SPH), cylindrical (CYL), and axial (AX) values which represent the refractive errors of the eyes. The results are displayed in the device and uploaded to a database which can be viewed at the website online. The device was able to provide a reliable measurement which can aid in conducting eye checkups. With this, refractive errors may be detected and corrected at an early stage to prevent severe vision impairments.