Adaptive Optics


Description:

Adaptive Optics is a technology aimed at improving the performance of optical systems by reducing the effects of rapidly changing optical distortion. It helps clear obstacles caused by the effects of imperfection in the cornea and lens of the eye, and blurriness of images. This technology is achieved by measuring the distortions in a wavefront and compensating for them with a spatial phase modulator such as a deformable mirror or liquid crystal array. There are two main factors that allows this technology to work. The first is a wavefront sensor called the Hartmann-Shack that is used to measure the abberation in the eyes. The second factor is the use of a deformable mirror to compensate for the aberrations detected in the eye.


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plane wavefronts
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aberrated wavefronts



Applications:

Adaptive Optics has been applied to and for a number of things. The original usage was to produce images of single cones in the living human eye. With the joining of optical coherence tomography, AO has helped collect the three dimensional images of living cone photo receptors. Common vision enhancers such as eyeglasses, contact lenses, and even certain laser eye surgeries only correct the two most common re-tractive errors, defocus and astigmatism, while AO makes it possible to do a complete analysis of the eye's optical errors.

A recently developed system, the INOVEO project, uses the principles of adaptive optics to image the eye at the cellular level. This may lead to earlier detection of conditions or diseases that may lead to vision problems. Prototypes used previous to the INOVEO project were impractical due to the size of the systems and the inability to correct the wide range of defects found in the human eye. This project resulted in the development of a completely new deformable mirror technology called mirao.

Adaptive Optics can be used to detect as well as treat retinal diseases. Due to the ability of the adaptive optic system to compensate for aberrations in the human eye that would normally interfere with observation, the use of these systems has the potential to allow for earlier and more accurate detection of diseases. This technology allows the reduction of a surgical laser's focal point to the diameter of a cell. This allows doctors to selectively treat single cells without damaging the healthy tissue surrounding them.

The CRX1 Adaptive Optics Visual Simulator makes use of adaptive optics technology to allow doctors to simulate the results of any corrective procedures in real time before any corrective action is taken. This allows patients to experience the benefits of any proposed procedure in real time before any action is actually taken. This system uses the irx3™ Wavefront Aberrometer and the mirao™ 52-d Electromagnetic Deformable Mirror to simulate the outcome of a procedure on an organic LED display placed in the field of view of the patient.

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CRX1 Adaptive Optics Visual Simulator



Web Resources:

The Center for Adaptive Optics
News Article on Adaptive Optics
http://www.imagine-eyes.com/

Terminology/Other:

Deformable mirror - allows the correction of optical aberrations.
Shack-Hartman Wavefront sensor - detects optical aberrations.
irx3 wavefront aberrometer
mirao 52-d electromagnetic deformable mirror

Citations:
http://www.cvs.rochester.edu/people/d_williams/ao_research/ao_research.htm
http://en.wikipedia.org/wiki/Adaptive_optics
http://www.imagine-eyes.com/content/view/100/115/
http://www.imagine-eyes.com/content/view/27/54/