School of Optometry
http://hdl.handle.net/2022/600
2018-02-23T14:25:50ZEffect of test sequence on fusional vergence ranges
http://hdl.handle.net/2022/21822
Effect of test sequence on fusional vergence ranges
Goss, David
Background. Vergence adaptation or prism adaptation is a well-known phenomenon, but the effect of testing order on fusional vergence ranges has not been widely studied. Methods. Sixty-two patients had fusional vergence ranges taken with rotary prisms in either a base-in, base-out, base-in order or a base-out, base-in, base-out order. Results. The results showed statistically significant reductions in some fusional vergence range findings as a result of preceding fusional vergence range testing. Base-in findings were affected more often by base-out testing than vice-versa. The most consistent change was a reduction in the distance base-in break of 1 to 3 prism diopters when it followed base-out testing. Conclusions. This study supports the recommendation in some texts that the effects of vergence adaptation on fusional vergence test findings can be minimized by performing base-in tests before base-out. However, these effects are generally small in amount.
1995-01-01T00:00:00ZMatlab Files for Fourier Analysis for Beginners
http://hdl.handle.net/2022/21366
Matlab Files for Fourier Analysis for Beginners
Thibos, Larry N.
Matlab files to accompany book developed to serve a graduate-level course called “Quantitative Methods for Vision Research” taught for many years at Indiana University School of Optometry, Bloomington, Indiana.
These matlab files were produced by a Macintosh computer running Matlab version 2015. Files with the extension *.m are unformatted text files that can be opened with any text editor. They are Matlab scripts and functions that can be opened and executed by Matlab. Files with the extension *.mat are binary data files that can be opened only by Matlab. These Matlab files are intended for readers of the monograph “Fourier Analysis for Beginners” who wish to review numerical examples and exercises mentioned in the text. The full text of the book can be downloaded at http://hdl.handle.net/2022/21365 .
2014-01-01T00:00:00ZFourier Analysis for Beginners
http://hdl.handle.net/2022/21365
Fourier Analysis for Beginners
Thibos, Larry N.
Fourier analysis is ubiquitous. In countless areas of science, engineering, and mathematics one finds Fourier analysis routinely used to solve real, important problems. Vision science is no exception: today's graduate student must understand Fourier analysis in order to pursue almost any research topic. This situation has not always been a source of concern. The roots of vision science are in "physiological optics", a term coined by Helmholtz which suggests a field populated more by physicists than by biologists. Indeed, vision science has traditionally attracted students from physics (especially optics) and engineering who were steeped in Fourier analysis as undergraduates. However, these days a vision scientist is just as likely to arrive from a more biological background with no more familiarity with Fourier analysis than with, say, French. Indeed, many of these advanced students are no more conversant with the language of
mathematics than they are with other foreign languages, which isn't surprising given the recent demise of foreign language and mathematics requirements at all but the most conservative universities. Consequently, a Fourier analysis course taught in a mathematics, physics, or engineering undergraduate department would be much too difficult for many vision science graduate students simply because of their lack of fluency in the languages of linear algebra, calculus, analytic geometry, and the algebra of complex numbers.
This introduction to the branch of mathematics called “Fourier analysis” was written for students who lack the mathematical background typically expected by authors of introductory textbooks of a similar title. The book was developed to serve a graduate-level course called “Quantitative Methods for Vision Research” taught for many years at Indiana University School of Optometry, Bloomington Indiana.Supplementary Matlab files for readers who wish to review numerical examples and exercises mentioned in the text can be downloaded from an accompanying record at http://hdl.handle.net/2022/21366 .
2014-01-01T00:00:00ZTesting of Lagrange multiplier damped least-squares control algorithm for woofer-tweeter adaptive optics
http://hdl.handle.net/2022/19128
Testing of Lagrange multiplier damped least-squares control algorithm for woofer-tweeter adaptive optics
Zou, W.; Burns, S.A.
A Lagrange multiplier-based damped least-squares control algorithm for woofer-tweeter (W-T) dual deformable-mirror (DM) adaptive optics (AO) is tested with a breadboard system. We show that the algorithm can complementarily command the two DMs to correct wavefront aberrations within a single optimization process: the woofer DM correcting the high-stroke, low-order aberrations, and the tweeter DMcorrecting the low-stroke, high-order aberrations. The optimal damping factor for a DMis found to be the median of the eigenvalue spectrum of the influence matrix of that DM.Wavefront control accuracy is maximized with the optimized control parameters. For the breadboard system, the residual wavefront error can be controlled to the precision of 0.03 μm in root mean square. The W-T dual-DM AO has applications in both ophthalmology and astronomy
2012-01-01T00:00:00Z