First used in astronomy to correct for blur in ground-based telescopes due to atmospheric turbulence, adaptive optics is now used in vision science to provide diffraction limited imaging of individual retinal cells and to determine the effect of ocular aberrations on the visual acuity and accommodation control. This book provides an introduction to adaptive optics as applied to vision science. The aim is to make the topics tangible for someone completely new to the field, regardless of their discipline. It covers all main concepts including how to develop a basic system from the ground up and also includes information on the current state-of-the-art systems.
Introduction. Origins of Adaptive Optics. Astronomy and Adaptive Optics.
Adaptive Optics and the Eye. The Eye as an Adaptive Optics System.
Imperfections in the Eye's Adaptive Optics System. History of Adaptive Optics
Applied to the Eye. Summary.
Chapter 2: Designing and Building a System for
Vision Science. Optical Design of a Basic System. The Importance of the
Pupil. Relay Telescopes. Optical Components. Field of View and Light Loss.
Removing Reflections. Light Sources. Choosing the wavelength. Choosing the
type of light source. Safety Considerations. Mounting and Aligning a System.
Mounting the Optics. Aligning the System. Stabilising the Subject. Summary.
Chapter 3: Measuring the Eye's Aberrations. Description of the Eye's
Aberrations. Rays to Wavefronts. Zernike Polynomials. Temporal Properties.
Shack-Hartmann Sensor. How it Works. Determining Spot Locations. Choosing the
Shack-Hartmann Components. Obtaining the Zernike Coefficients. Beyond
Conventional Shack-Hartmanns. Other Types of Sensors. Curvature Sensor.
Pyramid Sensor. Wavefront Sensorless Systems. Summary.
Chapter 4: Correcting
the Eye's Aberrations. How Correctors Work. Phase Conjugation. Factors to
Consider when Choosing a Corrector. Deformable Mirrors. Segmented.
Continuous. Liquid Crystals. Other Types of Corrector. Correctorless Systems.
Increasing System Correction Capabilities. Removing Defocus and Astigmatism.
Stroke Amplification. Summary.
Chapter 5: Controlling an Adaptive Optics
System. Open-Loop versus Closed-Loop Systems. Obtaining the Corrector
Signals. Via the Slopes. Via the Zernike Polynomials. Time Delays and their
Consequence. Origin of Time Delays. Instability. The Integral Controller. Why
it is Used. Doing a full Correction. Manipulating the Zernike Coefficients.
Measuring System Performance. Writing the Software. Summary.
Chapter 6:
Retinal Imaging with Adaptive Optics. Anatomy of the Retina. Instruments and
their Application. Flood Illumination Ophthalmoscope. Scanning Laser
Ophthalmoscope. Optical Coherence Tomographer. Multiconjugate Systems.
Multimodal Instruments. Summary.
Chapter 7: Vision Manipulation with Adaptive
Optics. Limits of Visual Acuity. Accommodation. Dual Channel Monocular
System. Binocular System. Visual Simulation and Blur Adaptation. Summary.
Chapter 8: The Future. Summary of what we can Currently Achieve. Limits and
how they can be Overcome. Appendix. Laser Safety calculationsTroubleshooting.
Karen Hampson is a researcher in the Bradford School of Optometry and Vision Science at Bradford University. Her primary area of research is the application of adaptive optics to vision science. She has worked in this field for 15 years and developed several adaptive optics systems from the ground up. Her interest in this area began with her PhD at Imperial College, which she completed in 2004. Her current projects include retinal imaging for detecting disease at the single cell level, and investigating how the aberrations of the eye influence focusing control in myopia. She is also secretary of the Institute of Physics Medical Physics Group and a committee member of the Optical Group.
