[OPTICAL REVIEW Vol. 13, No. 4 (2006) 207-211]
© 2006 The Optical Society of Japan

Measurement of Wavefront Aberration of Human Eye Using Talbot Image of Two-Dimensional Grating

Ryotaro SEKINE1, Takashi SHIBUYA1, Kazuhiko UKAI1,*, Shinichi KOMATSU1,2, Masayuki HATTORI1, Toshifumi MIHASHI3, Naoki NAKAZAWA3 and Yoko HIROHARA3

1Department of Applied Physics, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
2Material Research Laboratory for Bioscience and Photonics, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
3Topcon Corporation, 75-1 Hasunuma-cho, Itabashi-ku, Tokyo 174-8580, Japan

(Received January 16, 2006; Accepted April 5, 2006)

The measurement of human ocular aberration is now frequently performed because of the increase in refractive surgery on the human cornea. The Hartmann–Shack (H–S) wavefront sensor is considered to be the most useful wavefront sensor, and a calculation method for wavefront aberration has been established. New methods of measuring wavefront aberrations of human eyes, using the Talbot image of a two-dimensional grating as a wavefront sensor and local shift of the Talbot image to calculate tilt of the wavefront are shown. The shift of the Talbot image was determined by comparing the phases of fundamental spatial frequency between the grating and the local patch of the Talbot image by Fourier transformation. The actual experiment was performed using a modified commercially available wavefront analyzer. Using these methods, Talbot images were obtained from model eyes and a human eye, and wavefront shapes were successfully reconstructed. Wavefront aberrations can be measured even when the obtained image is degraded by defocusing or scattering.

Key words: Talbot image, wavefront sensor, human eye, wavefront aberration, two-dimensional grating, Fourier analysis

*Corresponding author. E-mail address: ukai@waseda.jp