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Clinical Optics Research LabIndiana University School of Optometry

Welcome to CORL!

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We are a group of scientists from around the world who participate in both basic and clinical studies designed to improve the visual quality of patients who are experiencing a variety of optical imperfections. Our diverse team has ongoing collaborations with colleagues in Spain, England, China as well as other labs at Indiana University.

CORL has helped design and evaluate many of the contact lenses and contact lens care products on the market today, helping millions of people around the world see.

We are always testing the newest ideas and products that may be available to you as a consumer in the future. To do this, however, we need your help by providing your feedback, such as how well you see, how comfortable you are, etc.

CORL performs cutting-edge translational clinical optics research. The goal of this research is to improve the vision and clinical care of patients by achieving the following aims:

  1. Evaluate and predict the success of refractive interventions and visual corrections
  2. Develop outcome measures to enhance a clinician’s ability to treat patients and the researchers ability to quantify improvements in care and determine causes for failures
  3. Improve ocular diagnostics for the detection, diagnosis, and correction of corneal disease
  4. Generate improvements in refractive interventions and visual corrections through controlled optical manipulations

We hope you find this website useful and informative. If you have any questions don’t hesitate to contact us.

Fourier Analysis for Beginners by prof. Larry N. Thibos

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Natural philosophy is written in this grand book the universe, which
stands continually open to our gaze. But the book cannot be understood
unless one first learns to comprehend the language and to read the
alphabet in which it is composed. It is written in the language of
mathematics, and its characters are triangles, circles, and other geometric
figures, without which it is humanly impossible to understand a single
word of it; without these, one wanders about in a dark labyrinth.

Galileo Galilei
Galileo Galilei, the father of experimental science.

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.
Prof. Larry N. Thibos (author)

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. It is for these students that the present course was developed.

To communicate with the biologically-oriented vision scientist requires a different approach from that typically used to teach Fourier analysis to physics or engineering students. The traditional sequence is to start with an integral equation involving complex exponentials that defines the Fourier transform of a continuous, complex-valued function defined over all time or space. Given this elegant, comprehensive treatment, the real-world problem of describing the frequency content of a sampled waveform obtained in a laboratory experiment is then treated as a trivial, special case of the more general theory. Here we do just the opposite. Catering to the concrete needs of the pragmatic laboratory scientist, we start with the analysis of real-valued, discrete data sampled for a finite period of time. This allows us to use the much friendlier linear algebra, rather than the intimidating calculus, as a vehicle for learning. It also allows us to use simple spreadsheet computer programs (e.g. Excel), or preferably a more scientific platform like Matlab, to solve real-world problems at a very early stage of the course.

With this early success under our belts, we can muster the resolve necessary to tackle the more abstract cases of an infinitely long observation time, complex-valued data, and the analysis of continuous functions. Along the way we review vectors, matrices, and the algebra of complex numbers in preparation for transitioning to the standard Fast Fourier Transform (FFT) algorithm built into Matlab. We also introduce such fundamental concepts as orthogonality, basis functions, convolution, sampling, aliasing, and the statistical reliability of Fourier coefficients computed from real-world data. Ultimately, we aim for students to master not just the tools necessary to solve practical problems and to understand the meaning of the answers, but also to be aware of the limitations of these tools and potential pitfalls if the tools are misapplied.

Related resources

Video Lecture: “Laplacians, Jacobians, and Gaussian curvature: A “deep-dive” into optical math” – prof. Larry N. Thibos.

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The lecture is prompted by a request for a deeper understanding of some of the vector algebra that is the foundation of the textbook method. That method is explained for optometric audiences in the attached paper, which will give you a sense of the “flavor” of the topic. Might not suit all tastes, but we must all learn to eat the bitter with the sweet 🙂 The lecture focuses on the geometrical properties of wavefronts that are used to compute the geometrical point-spread function. This is a very different problem from the more familiar Fourier optics calculation of the PSF based on physical optics. The math is actually easier for the geometrical optics method, but requires some familiarity with vector algebra concepts.

– prof. Larry N. Thibos.

Accompanying resources:

Participants Needed for Contact Lens Study; Ages 8-12

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Research Participants Needed Ages 8-12

 

Contact Lens Study at the Clinical Optics Research Lab, IU School of Optometry

Participants will look at letters far away and up close with different contact lenses. $40/hr compensation; up to 3 visits, up to 2 hours each

Email corl@indiana.edu for more information 

Clinical Optics Research Lab Indiana University – Bloomington 800 East Atwater Avenue Bloomington, IN 47405 812-855-5500 

 

Accommodative Behavior, Hyperopic Defocus, and Retinal Image Quality in Children Viewing Electronic Displays

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The prevalence of myopia and use of electronic displays by children has grown rapidly in recent years. We found that children viewing electronic displays, however, experience hyperopic defocus levels similar to those previously reported for other stimuli.

 

 

Please find our research article in the current issue of OVS.

The article can be assessed via the following link:

https://journals.lww.com/optvissci/Abstract/2020/08000/Accommodative_Behavior,_Hyperopic_Defocus,_and.2.aspx?fbclid=IwAR2Lg5npvA45un3VuMNdnEBh-SiPXHkX6zYTyUReDg4E-boHnEMY_EAq0yU

Indiana University School of Optometry Borish Center Photography Contest Results

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The Indiana University School of Optometry Borish Center for Ophthalmic Research’s annual photography contest winners have been announced. This year’s winner is “RITA” by Jacob Beam. The other finalists were Jacob Beam, “RAF” and Rebecca Cambridge, “See?”. The theme for the 2020 contest was “20/20 Vision.” These photos will be framed and hung on the 3rd floor of the Indiana University School of Optometry.

Thank you to everyone who participated in this year’s photography contest and we look forward to seeing your entries next year!

“RITA” by Jacob Beam (First Place)

“RAF” by Jacob Beam (Finalist)


“See?” by Rebecca Cambridge (Finalist)

Participate in the Indiana University Borish Center Photography Contest!

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The goal of this contest is to utilize artistic still images to tell a compelling story, which will help to foster interest and awareness of the importance of the eye and vision care to individuals and society.

Details of the contest can be found in the flyer above and entries can be submitted in the link below. Contest entries will be accepted from February 1 – April 1, 2020 and awards will be provided.

https://redcap.uits.iu.edu/surveys/?s=FX7HFJXY4J

Participate in the Indiana University Borish Center Photography Contest!

Posted on by maddy


The goal of this contest is to utilize artistic still images to tell a compelling story, which will help to foster interest and awareness of the importance of the eye and vision care to individuals and society.

Details of the contest can be found in the flyer above and entries can be submitted in the link below. Contest entries will be accepted from February 1 – April 1, 2019 and awards will be provided.

https://redcap.uits.iu.edu/surveys/?s=MNENTRTX78

Review of Optometry Jan 2019 (Myopia Issue)

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The rapid increase in myopia prevalence over the last 50 years has occurred simultaneously during a period of rapid technological advances, resulting in the dominant use of electronic devices for displaying everything from text, pictures, movies, games and more.

Myopia is accelerating rapidly in 21st Century and predictions suggest 50% of the world being myopic by 2050. Know more about how myopia is impacting our lives and ways to prevents its progression in Myopia Issue of Review of Optometry. The snippet of the research project led by PhD Student, Raman Sah focused on “Myopia and Electronic devices” is featured in Myopia Issue of Review of Optometry.

The article can be assessed via the following link:
Myopia and Use of Electronic Devices

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Clinical Optics Research Lab, Indiana University School of Optometry
800 E. Atwater Avenue, Bloomington, IN 47405 (see map)
Tel: 812-855-5500, or contact us by email.
Website design & photography: Matt Jaskulski.