William Ayliffe--The Eye and Vision (2011-2014)

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source: GreshamCollege       2011年8月11日
A series of free public ophthalmology lectures by William Ayliffe, Gresham Professor of Physic. All information is available on the Gresham College website: www.gresham.ac.uk
The transcript and downloadable versions of the lectures are available from the Gresham College website: http://www.gresham.ac.uk/lectures-and...

1:03:21 Fun with Visual Illusions
Visual illusions entertain and astonish us. How and why they occur is due to the way our visual system processes information. The study of visual illusions leads to many surprising and counterintuitive conclusions about vision. How illusions occur will be illustrated with many beautiful, well-known examples from art history as well as novel images. Following this talk the world out there will seem to be a very different place.
1:01:41 Correction of Optical Defects: From Spectacles to Lasers 
Despite sophisticated techniques; Laser, intraocular surgery and contact lenses; spectacles remain the most popular method for correcting optical defects of the eye.  Roger Bacon (1266) proposed that convex lenses could be used for elderly people with failing sight, replacing crystals used for magnification.  Printing exploded the need for spectacles and by the close of the 20th century amazing advances in surgery corrected vision defects.
1:00:06 Diabetes, Hypertension and Vascular Diseases of the Eye 
The transparent tissues of the eye allow light to reach the retina.  This highly metabolic tissue requires oxygen delivered by the blood vessels, which are damaged by disease.  Diabetic retinopathy is the commonest cause of blindness in the working-age population and in later life hypertension adds to this toll.  The eyes maybe the mirror of the soul, but they certainly are a window into our general health.  This lecture traces the story from the development of the ophthalmoscope to modern treatments.
52:06 Blindness in Children: The Global Perspective
It is not only a personal tragedy to be born or to acquire blindness in early life but also a major socio-economic problem.  Tragically many cases are preventable. Professor Gilbert will explain why children become blind and how programs instigated worldwide treatment and prevent blindness.
55:22 Why we see what we do 
The visual system has developed to allow us to navigate in a complex and dangerous world in order to find food and to avoid danger.  This survival system works by building a complex three-dimensional model based on two-dimensional data from the retina.  This model is tested against "reality" and checked with information from other senses and updated if needed.  The brain suppresses the complexity of this processing and we believe that vision is instantaneous, real and effortless.  But is seeing just an illusion?
53:53 How do we see Colour? 
Evolving in a silent, dark world, organisms developed receptors that could detect and differentiate components of the electromagnetic spectrum from the sun. Computation of the proportions of different wavelengths emitted from objects is used to form the perception of colour by the visual system, enhancing the ability to differentiate objects from background.  The beauty of colour, used by individuals, artists and commerce is important in all cultures from pre-history to the present.
59:44 The Ageing Eye
As the eye ages, profound structural changes occur, leading to visual impairment and even blindness.  Exciting discoveries in biological science and surgery are opening up possible new treatments for these common conditions.  The economic impact on society as populations become older and the role of governments and charities will be discussed.
1:01:37 The Evolution of Vision
Did the eye evolve and, if so, how?  Creationists and evolutionary biologists have argued over this controversy since Darwin published On the Origin of Species in 1859.  About 830 million years ago, in the Cambrian period, an explosion of the number of species occurred, and the possession of vision was a major survival advantage.  Did these diverse eyes evolve separately many different times?  Recent genetic research on eyes in insects and mammals reveals that they are more closely related than suspected.
1:00:46 Vision and the Artist 
Visual disorders affect the way we see, and therefore would be expected to influence how we depict the world in drawings and paintings.  This fascinating subject is explored using images created by artists with known defects.  We examine how possible defects in the vision of artists for whom we have little information about their eyesight, might explain how they produced their individual style.  How the physiology of vision is deliberately used by artists to create stunning visual effects, and how ancient artists achieved similar results by deduction will be explored.
10 59:04 Animal Eyes
How does my dog see?  Do eagles have better vision than humans?  This homocentric view of vision with its associated mythology is explored in this review of survival strategies used by various animals in their environments.  The way we see is predicated by what we need to see. From prawns to birds we will explore how eyes have adapted to be perfect for the tasks assigned to them.  No longer can we claim that our human vision is the standard by which other animals must be judged as either inferior or superior.
11 58:55 Technology and Vision - Professors William Ayliffe, John Marshall MBE and Dan Reinstein
The discipline of Ophthalmology is recognised both as an early adopter of new technology and a developer of novel techniques.  Soon after lasers were invented, they were being used to treat diabetic eyes and new lasers developed into exquisite tools for reshaping the cornea in refractive surgery.  In electronics the possibility of artificial vision in blind people and robots is becoming reality.  In biology, advances in transplantation science have increased the numbers of treatable conditions.  From stem cells to genetic manipulation, technological advances have the potential to cure blindness in ways not thought possible a decade ago.
12 1:00:03 The Window on the Soul 
Vision is the dominant sense through which sighted people have developed our culture.  It requires enormous computational power: over half of the human brain is assigned to create vision from the electrical impulses generated by light.  Since ancient times, the beauty of the visual world has fascinated us.  People born blind have learned extraordinary strategies.  Integration of this information will allow robots to function more efficiently and give blind people new insights on their environment.
13 55:03 The Eye at War: Preventing and treating combat injuries 
Deliberately blinding opponents has always been part of warfare.
Sophisticated protective armour has ancient origins. With the incrementally rising incidence of eye injuries with each successive modern war, eye protection had to be re-invented with often bizarre results.
As the face and eye became a major site of injury; modern plastic surgery was created from the carnage of the trenches in WWI. Further advances occurred with the treatment of burned pilots in the Second World War. The co-operation of artists, sculptors and surgeons led to rehabilitation of many of these people and to a change in public perception of patients with such injuries.
An extraordinary story of extraordinary people reveals how the dedication and humanity of these surgeons led to much that we take for granted in our modern world.
14 1:02:35 Transplantation and the Eye 
The first successful solid organ transplant was the cornea in Moravia in 1905. However both science and clinical tools then available were unable to allow further advances. The discovery of the natural barriers to transplantation enabled understanding of the biology of transplants and now livers, hearts, kidneys and corneas are routinely transplanted.
In ophthalmology the advances in microsurgery and microscopes have led to better visual outcomes and less loss of donor organs. Indeed it is now possible to transplant each individual layer of the cornea.
These breathtaking procedures have revolutionised the treatment of blinding diseases of the eye.
Attention is now turning to developing techniques for transplanting retinal tissues opening up potential hope for those suffering from macular degeneration, the commonest cause of loss if sight in the elderly population.
15 1:00:14 Return of the Microbes: How infections are once more taking over
After decades of improvement in treatment many microbes were thought to be on the edge of extinction, now they appear to be resurgent: http://www.gresham.ac.uk/lectures-and...
Whilst this was achieved with smallpox, the promise if eradication of trachoma and river blindness remains elusive. Furthermore the increasing resistance if organisms to antibiotics is becoming and urgent challenge in all parts of the world. The resurgence if Tuberculosis is a particular problem. How these organisms cause disease, blindness, how they are treated and how we may eradicate them concerns each and every one of us. The answer is becoming more difficult and more urgent to find.
16 1:06:34 Eye on the Future
This lecture examines how the treatment of infection , injury and disease will change as science progresses: http://www.gresham.ac.uk/lectures-and...
Gene therapy, stem cells antibodies, RNA interference and nanotechnology have all been investigated as potential treatments for a variety of eye diseases. Some of these have already entered clinical use whilst others remain in investigational stage. These new exciting and exotic sounding technologies are likely to play an increasing role in eye-care. What they are, how they work and what they are likely to achieve will be discussed in this lecture.
17 1:04:07 Artificial Eye, Artificial Vision: How does my robot see?
Seeing robots and blind patients with artificial vision are already a reality. What was thought impossible ten years ago is now commonplace. What will the next yen years reveal to us? http://www.gresham.ac.uk/lectures-and...
Recent technological improvements have allowed further miniaturisation of electronic components. This has allowed the implantation of devices that can replace the initial photoreception by rods and cones in patients with absence of these cells from disease. Artificial vision is also needed for independently mobile machines. Understanding the human visual system has also led to improvements of robot navigation. For instance programming robots with visual illusions improves their performance in complex environments. Seeing robots and blind patients with artificial vision are already a reality. Truly amazing inventions are just steps away. What was thought impossible ten years ago is now commonplace. What will the next yen years reveal to us?
18 1:14:56 The Iconography of Blindness: How artists have portrayed the blind
A world renowned eye surgeon examines the portrayal the blind in art throughout the centuries, and discusses what we can infer from these depictions: http://www.gresham.ac.uk/lectures-and...
Blind people have always been with us. The attitudes of society have varied over the years from disgust and horror to sympathy and kindness. How a painter depicts whether a subject cannot see in contrast to those who can us an interesting subject with a surprising number of examples. Some if these images clearly reveal the painters attitudes to blinding disability. Many are sensitive and beautiful creations in their own right. Looking at these works of art challenges our own preconceptions about blind people

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