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Journal of Biomedical Optics

Off-axis wave front measurements for optical correction in eccentric viewing
Author(s): Linda K. Lundström; Peter Unsbo; Jörgen Gustafsson
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Paper Abstract

In a previous study we have shown that correction of peripheral refractive errors can improve the remaining vision of subjects with large central visual field loss. Measuring peripheral refractive errors with traditional methods is often difficult due to low visual acuity and large aberrations. Therefore a Hartmann–Shack sensor has been designed to measure peripheral wave front aberrations in subjects using eccentric viewing. The sensor incorporates an eye tracker and analyzing software designed to handle large wave front aberrations and elliptic pupils. To ensure that the measurement axis is aligned with the direction of the subject's preferred retinal location, a special fixation target has been developed. It consists of concentric rings surrounding the aperture of the sensor together with a central fixation mark along the measurement axis. Some initial measurements on subjects using eccentric viewing have been performed successfully. As a first step in improving the peripheral optics of the eye, the wave front has been used to calculate the eccentric refraction. This refraction has been compared to the refraction found with the PowerRefractor instrument. Measuring the off-axis wave front is a fast way to assess the optical errors in the subject's eccentric viewing angle and to better understand the problems of eccentric correction.

Paper Details

Date Published: 1 May 2005
PDF: 7 pages
J. Biomed. Opt. 10(3) 034002 doi: 10.1117/1.1920587
Published in: Journal of Biomedical Optics Volume 10, Issue 3
Show Author Affiliations
Linda K. Lundström, Kungliga Tekniska Högskolan (Sweden)
Peter Unsbo, Kungliga Tekniska Högskolan (Sweden)
Jörgen Gustafsson, Lunds Univ. (Sweden)


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