Related topics: nerve cells , blindness
Retina
hideThe vertebrate retina is a light sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centers of the brain through the fibers of the optic nerve.
In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system (CNS).. It is the only part of the CNS that can be imaged non-invasively in the living organism.
The retina is a complex, layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light and provide black-and-white vision, while cones support daytime vision and the perception of colour. A third, much rarer type of photoreceptor, the photosensitive ganglion cell, is important for reflexive responses to bright daylight.
Neural signals from the rods and cones undergo complex processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Several important features of visual perception can be traced to the retinal encoding and processing of light.
For more information about Retina, read the full article at
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News tagged with retina
Two Retinal Imaging Display Devices at Prototype Stage
Electronics / Consumer & Gadgets
Oct 30, 2009 |
4.9 / 5 (28) |
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(PhysOrg.com) -- NEC and Brother are both developing wearable prototype devices that use Retinal Imaging Display (RID) technology to project images directly on the wearer's retina. NEC's gadget is designed ...
Mammals can be stimulated to regrow damaged inner retina nerve cells
Biology /
Nov 24, 2008 |
4.7 / 5 (22) |
3
Researchers at the University of Washington (UW) have reported for the first time that mammals can be stimulated to regrow inner nerve cells in their damaged retinas. Located in the back of the eye, the retina's role in vision ...
Scientists Find First Creature With Eyes That Use Both Refractive and Reflective Optics
Jan 27, 2009 |
4.2 / 5 (17) |
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Florida Atlantic University researcher and member of the Center for Ocean Exploration and Deep-Sea Research at Harbor Branch Oceanographic Institute, Dr. Tamara Frank, was part of an international research ...
An 'eye catching' vision discovery
Medicine & Health / Neuroscience
Jul 26, 2009 |
4.4 / 5 (11) |
0
Nearly all species have some ability to detect light. At least three types of cells in the retina allow us to see images or distinguish between night and day. Now, researchers at the Johns Hopkins School of ...
Researchers discover mechanism that helps humans see in bright and low light
Medicine & Health / Neuroscience
Oct 13, 2009 |
4.9 / 5 (9) |
0
Ever wonder how your eyes adjust during a blackout? When we go from light to near total darkness, cells in the retina must quickly adjust. Vision scientists at Washington University School of Medicine in St. ...
Researchers' vision: restoring sight through artificial retinas
Dec 30, 2008 |
4.4 / 5 (8) |
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Scientists are testing artificial retinas that they hope can restore partial sight to people who've lost their vision to the most common causes of blindness.
Nerve cells live double lives
Medicine & Health / Neuroscience
Oct 06, 2009 |
4.6 / 5 (7) |
2
(PhysOrg.com) -- Scientists at the Friedrich Miescher Institute for Biomedical Research (part of the Novartis Research Foundation) have identified a new neural circuit in the retina responsible for the detection ...
Researchers create first model for retina receptors
Sep 30, 2008 |
4.4 / 5 (7) |
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A team of scientists at the University of Oklahoma Health Sciences Center has created the first genetic research model for a microscopic part of the eye that when missing causes blindness. The research appears in a recent ...
A master mechanism for regeneration?
Medicine & Health / Neuroscience
Oct 19, 2009 |
4.8 / 5 (6) |
1
ANN ARBOR, Mich.---Biologists long have marveled at the ability of some animals to re-grow lost body parts. Newts, for example, can lose a leg and grow a new one identical to the original. Zebrafish can re-grow fins.
Bright lights, not-so-big pupils
Dec 31, 2008 |
4.2 / 5 (6) |
2
A team of Johns Hopkins neuroscientists has worked out how some newly discovered light sensors in the eye detect light and communicate with the brain. The report appears online this week in Nature.
Researchers develop camera for the blind
Jan 12, 2009 |
5 / 5 (5) |
2
(PhysOrg.com) -- Elizabeth Goldring smiles as she shows a visitor photos she's taken — and can see — with her blind eye.
Vision researchers see unexpected gain a year into blindness trial
Aug 12, 2009 |
5 / 5 (5) |
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Scientists have discovered that even in adults born with extremely impaired sight, the brain can rewire itself to recognize sections of the retina that have been restored by gene therapy.
Discoveries shed new light on how the brain processes what the eye sees
Medicine & Health / Neuroscience
Jun 02, 2009 |
5 / 5 (4) |
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Researchers at the Center for Molecular and Behavioral Neuroscience (CMBN) at Rutgers University in Newark have identified the need to develop a new framework for understanding "perceptual stability" and how ...
How the retina works: Like a multi-layered jigsaw puzzle of receptive fields
Apr 07, 2009 |
5 / 5 (3) |
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About 1.25 million neurons in the retina -- each of which views the world only through a small jagged window called a receptive field -- collectively form the seamless picture we rely on to navigate our environment. ...
Technology to Treat Blindness Earns Award
Jul 23, 2009 |
5 / 5 (3) |
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Research performed at Caltech as part of a collaborative U.S. Department of Energy-funded artificial-retina project designed to restore sight to the blind has received one of R&D Magazine's 2009 R&D 100 Awards. ...
