| EPSRC Reference: |
EP/G015473/1 |
| Title: |
Binocular adaptive optics system for the study of the ocular accommodation system in humans |
| Principal Investigator: |
Mallen, Professor E |
| Other Investigators: |
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| Researcher Co-Investigators: |
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| Project Partners: |
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| Department: |
Faculty of Life Sciences |
| Organisation: |
University of Bradford |
| Scheme: |
Standard Research |
| Starts: |
20 October 2008 |
Ends: |
19 October 2011 |
Value (£): |
327,015
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| EPSRC Research Topic Classifications: |
| Med.Instrument.Device& Equip. |
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| EPSRC Industrial Sector Classifications: |
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| Related Grants: |
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| Panel History: |
| Panel Date | Panel Name | Outcome |
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16 Sep 2008
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Healthcare Engineering Panel (Eng)
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Announced
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Summary on Grant Application Form |
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Myopia (short-sight) is a common error in the focusing system of the human eye. Myopic individuals can see clearly at near, but objects in the distance are blurred. The condition affects around 25% of people in the West, and 75% of the Far Eastern population. As well as being reliant on corrective spectacle or contact lenses, myopic individuals are also at greater risk of developing other eye conditions, such as glaucoma and retinal detachment. It is therefore of utmost importance to find ways of preventing the onset of myopia and limiting progression of this condition. It is known that nearwork is a risk factor in myopia development, but as yet the specific aspects of a close-up task that may cause myopia are not known. The project described here aims to identify some of these factors so that they can be eliminated, perhaps by the use of specially-designed contact lenses, thereby reducing the risk of myopia development for future generations. One factor that has been studied in detail in animals is the quality of the image formed on the retina, the light-sensitive layer at the back of the eye, by the optics of the eye. It has been shown that if the retinal image is degraded, the eye is more likely to become myopic, compared with an eye with a sharply focused retinal image. In human eyes an automatic focussing system, the accommodation response, is used to maintain a clear retinal image during nearwork. Errors in the accommodation response, such as an inadequate response for a given near task, have been implicated in the development of myopia. The exact mechanism for the guiding of the accommodation response is open to debate, but recent experiment work has suggested that small fluctuations in the power of the flexible lens in the eye may act as a cue for the amount of focussing power required for a given task. A particular area of interest in the proposed work is the role of small errors in focus, the so-called higher-order aberrations of the eye. Measurement of these aberrations can be achieved using a high-precision video camera and special lens array; the Shack-Hartmann sensor. Using this sensor, it is possible to obtain a record of the fluctuation in aberrations during a variety of visual tasks. Using a mirror with a deformable surface, it is possible to correct the aberrations of the eye. A Shack-Hartmann sensor and deformable mirror form the basis of an adaptive optics system. Such systems have been used in the past by astronomers to improve the images of stars seen via telescopes. Adaptive optics can be applied to the eye to improve the retinal image quality. Conversely, adaptive optics can also be used to degrade various aspects of the retinal image, and as such can be used to test the role of retinal image quality in maintaining accurate focussing of the eye during reading and close-up work. We wish to use this feature of adaptive optics technology to investigate how the focussing system of human eyes operates, and how this is coordinated between the two eyes of an individual. Therefore, in the proposed research project, we wish to investigate the role of these fluctuations in focussing power in both eyes simultaneously; to date this has not been attempted, and appropriate instrumentation for these investigations is not currently in existence. A significant aspect of this project will be the development of an adaptive optics system that is capable of measuring and correcting fluctuations in focus and higher-order aberrations of both eyes simultaneously. This will be the first instrument of its kind. The instrument will then be used to investigate the focussing of the eyes during a number of near visual tasks. Further work will examine how convergence eye movements (inward movement of the eyes during reading) interact with eye focus and ocular aberration fluctuations. The proposed work will increase our understanding of the role of nearwork and ocular aberrations in the development and progression of myopia.
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.brad.ac.uk |