The visual system is the part of the nervous system which allows organisms to see. The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also It interprets the information from visible light to build a representation of the world surrounding the body. With regard to living things, a body is the integral physical material of an individual The visual system has the complex task of (re)constructing a three dimensional world from a two dimensional projection of that world. The psychological manifestation of visual information is known as visual perception. In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also

Introduction

This article mostly describes the visual system of mammals, although other "higher" animals have similar visual systems. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands In this case, the visual system consists of:

• The eye, especially the retina
• The optic nerve
• The optic chiasma
• The optic tract
• The lateral geniculate body
• The optic radiation
• The visual cortex

Different species are able to see different parts of the light spectrum; for example, bees can see into the ultraviolet,^[1] while pit vipers can accurately target prey with their infrared imaging sensors. The visual system is the part of the Nervous system which allows organisms to see. The visual system is the part of the Nervous system which allows organisms to see. The visual system is the part of the Nervous system which allows organisms to see. The visual system is the part of the Nervous system which allows organisms to see. The visual system is the part of the Nervous system which allows organisms to see. The visual system is the part of the Nervous system which allows organisms to see. The visual system is the part of the Nervous system which allows organisms to see. The visual system is the part of the Nervous system which allows organisms to see. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies Bees are flying Insects closely related to Wasps and Ants Bees are a Monophyletic lineage within the superfamily Apoidea Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Common names: pit vipers pitvipers The Crotalinae, or crotalines are a subfamily of venomous vipers found Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of ^[2]

Optical layout of the eye The image projected onto the retina is inverted due to the optics of the eye.

History

In the second half of the 19th century, many motifs of the nervous system were identified such as the neuron doctrine and brain localisation, which related to the neuron being the basic unit of the nervous system and functional localisation in the brain, respectively. The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself The neuron doctrine is the now fundamental idea that Neurons are the basic structural and functional units of the Nervous system. Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information These would become tenets of the fledgling neuroscience and would support further understanding of the visual system. Neuroscience is a field devoted to the scientific study of the nervous system

The notion that the cerebral cortex is divided into functionally distinct cortices now known to be responsible for capacities such as touch (somatosensory cortex), movement (motor cortex), and vision (visual cortex), was first proposed by Franz Joseph Gall in 1810. The cerebral cortex is a structure within the Brain that plays a key role in Memory, Attention, perceptual Awareness, Thought, The lateral postcentral gyrus is a prominent structure in the Parietal lobe of the human Brain and an important landmark Motor cortex is a term that describes regions of the Cerebral cortex involved in the planning control and execution of voluntary motor functions The term visual cortex refers to the primary visual cortex (also known as striate cortex or Franz Joseph Gall ( March 9, 1758 - August 22, 1828) was a Neuroanatomist, physiologist, and pioneer in the study of the Year 1810 ( MDCCCX) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Common year ^[3] Evidence for functionally distinct areas of the brain (and, specifically, of the cerebral cortex) mounted though-out the 19th century with discoveries by Paul Broca of the language centre (1861), and Gustav Fritsch and Edouard Hitzig of the motor cortex (1871). Paul Pierre Broca ( June 28, 1824 &ndash July 9, 1880) was a French Physician, Anatomist, and Anthropologist Year 1861 ( MDCCCLXI) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a Common Gustav Theodor Fritsch ( March 5, 1837 - June 12, 1927) was a German Anatomist and Physiologist from Cottbus Eduard Hitzig ( February 6, 1839 - August 20, 1907) was a German Neuropsychiatrist from Berlin. Year 1871 ( MDCCCLXXI) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common ^[3][4] Based on selective damage to parts of the brain and the functional effects this would produce (lesion studies), David Ferrier proposed that visual function was localised to the parietal lobe of the brain in 1876. Sir David Ferrier ( January 13, 1843 – March 19, 1928) was a pioneer Scottish Neurologist and The parietal lobe is a lobe in the Brain. It is positioned above (superior to the Occipital lobe and behind (posterior to the Frontal lobe. Year 1876 ( MDCCCLXXVI) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian Calendar (or a Leap year ^[4] In 1881, Hermann Munk more accurately located vision in the occipital lobe, where the primary visual cortex is now known to be. Year 1881 ( MDCCCLXXXI) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a Common Hermann Munk (1839-1912 was a Jewish German physiologist. He was born at Posen, studied at Berlin and Göttingen, The occipital lobe is the visual processing center of the Mammalian Brain containing most of the anatomical region of the Visual cortex. The term visual cortex refers to the primary visual cortex (also known as striate cortex or ^[4]

Biology of the visual system

Eye

Main article: Eye

The eye is a complex biological device. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain The functioning of a camera is often compared with the workings of the eye, mostly since both focus light from external objects in the visual field onto a light-sensitive medium. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain The term visual field is sometimes used as a Synonym to Field of view, though they do not designate the same thing In the case of the camera, this medium is film or an electronic sensor; in the case of the eye, it is an array of visual receptors. With this simple geometrical similarity, based on the laws of optics, the eye functions as a transducer, as does a CCD camera. A transducer is a device usually electrical, electronic, Electro-mechanical, Electromagnetic, Photonic, or Photovoltaic A charge-coupled device ( CCD) is an analog Shift register, that enables the transportation of analog signals (electric charges through successive stages (capacitors

Light entering the eye is refracted as it passes through the cornea. Refraction is the change in direction of a Wave due to a change in its Speed. The cornea is the transparent front part of the Eye that covers the iris, Pupil, and Anterior chamber. It then passes through the pupil (controlled by the iris) and is further refracted by the lens. The pupil is the hole that is located in the center of the iris of the eye and that controls the amount of light that enters the Eye. The iris consists of Pigmented Fibrovascular tissue known as a stroma. The lens is a transparent biconvex structure in the Eye that along with the Cornea, helps to Refract Light to be focused The cornea and lens act together as a compound lens to project an inverted image onto the retina.

S. Ramón y Cajal, Structure of the Mammalian Retina, 1900

Retina

Main article: Retina

The retina consists of a large number of photoreceptor cells which contain a particular protein molecule called an opsin. Santiago Ramón y Cajal ( May 1 1852 &ndash October 17 1934) was a Spanish histologist, Physician, and Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The vertebrate retina is a light sensitive part inside the inner layer of the Eye. The vertebrate retina is a light sensitive part inside the inner layer of the Eye. Photoreceptor can refer to In anatomy/cell biology Photoreceptor cell: a photosensitive cell most commonly referring to a specialized type of neuron Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by Opsins are a group of light-sensitive 35-55 kDa membrane-bound G protein-coupled receptors of the Retinylidene protein family found in Photoreceptor cells In humans, two types of opsins are involved in vision: rod opsins and cone opsins. Rod cells, or rods, are Photoreceptor cells in the Retina of the Eye that can function in less intense Light than can the other type Cone cells, or cones, are Photoreceptor cells in the Retina of the Eye which function best in relatively bright Light. (A third type, melanopsin in some of the retinal ganglion cells, part of the body clock mechanism, is probably not involved in vision. Melanopsin is a Photopigment found in specialized Photosensitive ganglion cells of the Retina that are involved in the regulation of Circadian rhythms ) An opsin absorbs a photon (a particle of light) and transmits a signal to the cell through a signal transduction pathway, resulting in hyperpolarization of the photoreceptor. In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called In Biology, signal transduction refers to any process by which a cell converts one kind of signal or stimulus into another (For more information, see photoreceptor). Photoreceptor can refer to In anatomy/cell biology Photoreceptor cell: a photosensitive cell most commonly referring to a specialized type of neuron

Rods and cones differ in function. Rods are found primarily in the periphery of the retina and are used to see at low levels of light. Cones are found primarily in the center (or fovea) of the retina. The fovea, also known as the fovea centralis, is a part of the Eye, located in the center of the Macula region of the Retina. There are three types of cones that differ in the wavelengths of light they absorb; they are usually called short or blue, middle or green, and long or red. In Physics wavelength is the distance between repeating units of a propagating Wave of a given Frequency. Cones are used primarily to distinguish color and other features of the visual world at normal levels of light.

In the retina, the photoreceptors synapse directly onto bipolar cells, which in turn synapse onto ganglion cells of the outermost layer, which will then conduct action potentials to the brain. A bipolar cell is a type of Neuron which has two extensions Bipolar cells are specialized sensory neurons for the transmission of special senses A ganglion cell (more correctly a retinal ganglion cell or RGC) is a type of Neuron typically located near the inner surface of the Retina In Neurophysiology, the action potential is a self-regenerating Wave of Electrochemical activity that allows Nerve cells to carry a signal The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain A significant amount of visual processing arises from the patterns of communication between neurons in the retina. Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information About 130 million photoreceptors absorb light, yet roughly 1. 2 million axons of ganglion cells transmit information from the retina to the brain. An axon or nerve fiber is a long slender projectionof a nerve cell or Neuron, that conducts electrical impulses away from the neuron's Cell The processing in the retina includes the formation of center-surround receptive fields of bipolar and ganglion cells in the retina, as well as convergence and divergence from photoreceptor to bipolar cell. The receptive field of a sensory Neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron In addition, other neurons in the retina, particularly horizontal and amacrine cells, transmit information laterally (from a neuron in one layer to an adjacent neuron in the same layer), resulting in more complex receptive fields that can be either indifferent to color and sensitive to motion or sensitive to color and indifferent to motion. Horizontal cells are the laterally interconnecting neurons in the outer plexiform layer of the Retina of mammalian eyes Amacrine cells are Interneurons in the Retina. Amacrine cells are responsible for 70% of input to retinal ganglion cells The receptive field of a sensory Neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron In Physics, motion means a constant change in the location of a body

The final result of all this processing is five different populations of ganglion cells that send visual (image-forming and non-image-forming) information to the brain:

1. M cells, with large center-surround receptive fields that are sensitive to depth, indifferent to color, and rapidly adapt to a stimulus;
2. P cells, with smaller center-surround receptive fields that are sensitive to color and shape;
3. K cells, with very large center-only receptive fields that are sensitive to color and indifferent to shape or depth;
4. another population that is intrinsically photosensitive; and
5. a final population that is used for eye movements. Depth perception is the visual ability to perceive the world in three Dimensions Although any animal capable of moving around its environment must be able to The shape ( OE sceap Eng created thing) of an object located in some space refers to the part of space occupied by the object as determined Photosensitive ganglion cells, or melanopsin-containing ganglion cells, are a recently discovered type of nerve cell in the Retina of the mammalian

A 2006 University of Pennsylvania study calculated the approximate bandwidth of human retinas to be about 8960 kilobits per second, whereas guinea pig retinas transfer at about 875 kilobits. The University of Pennsylvania (also known as Penn) is a private University located in Philadelphia, Pennsylvania, USA. The Guinea pig (also commonly called the cavy after its scientific name Cavia porcellus) is a species of Rodent belonging to the family Caviidae ^[5]

In 2007 Zaidi and co-researchers on both sides of the Atlantic studying patients without rods and cones, discovered that the novel photoreceptive ganglion cell in humans also has a role in conscious and unconscious visual perception. ^[6][7][8] The peak spectral sensitivity was 481nm. This shows that there are two pathways for sight in the retina - one based on classic photoreceptors (rods and cones) and the other, newly discovered, based on photoreceptive ganglion cells which act as rudimentary visual brightness detectors.

Photochemistry

Main article: Visual cycle

In the visual system, retinal, technically called retinene₁ or "retinaldehyde", is a light-sensitive retinene molecule found in the rods and cones of the retina. Visual phototransduction is a process by which Light is converted into Electrical signals in the Rod cells Cone cells and Photosensitive ganglion The Retinenes (Retinene1 and Retinene2 are chemical derivatives of the dietary supplement Vitamin A (see Retinol The vertebrate retina is a light sensitive part inside the inner layer of the Eye. Retinal is the fundamental structure involved in the transduction of light into visual signals, i. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 e. nerve impulses in the ocular system of the central nervous system. In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. In the presence of light, the retinal molecule changes configuration and as a result a nerve impulse is generated.

Fibers to thalamus

Optic nerve

Main article: Optic nerve

Information flow from the eyes (top), crossing at the optic chiasma, joining left and right eye information in the optic tract, and layering left and right visual stimuli in the lateral geniculate nucleus. The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain The optic chiasm ( Greek χίασμα "crossing" from the Greek χλαζειν 'to mark with an X' after the Greek letter ' Χ ' chi) is the The optic tract is a part of the Visual system in the Brain. It is a continuation of the Optic nerve and runs from the Optic chiasm (where The lateral geniculate nucleus ( LGN) of the Thalamus is a part of the Brain, which is the primary processor of visual information received from the V1 in red at bottom of image. The term visual cortex refers to the primary visual cortex (also known as striate cortex or (1543 image from Andreas Vesalius' Fabrica)

The information about the image via the eye is transmitted to the brain along the optic nerve. Andreas Vesalius ( Brussels, December 31, 1514 - Zakynthos, October 15, 1564) was an anatomist, Physician Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain. Different populations of ganglion cells in the retina send information to the brain through the optic nerve. About 90% of the axons in the optic nerve go to the lateral geniculate nucleus in the thalamus. An axon or nerve fiber is a long slender projectionof a nerve cell or Neuron, that conducts electrical impulses away from the neuron's Cell The lateral geniculate nucleus ( LGN) of the Thalamus is a part of the Brain, which is the primary processor of visual information received from the The thalamus (from Greek θάλαμος = room chamber, IPA= /ˈθæləməs/ is a pair and symmetric part of the brain These axons originate from the M, P, and K ganglion cells in the retina, see above. An axon or nerve fiber is a long slender projectionof a nerve cell or Neuron, that conducts electrical impulses away from the neuron's Cell This parallel processing is important for reconstructing the visual world; each type of information will go through a different route to perception. In Psychology and the Cognitive sciences perception is the process of attaining awareness or understanding of sensory Information. Another population sends information to the superior colliculus in the midbrain, which assists in controlling eye movements (saccades). The superior colliculus ( Latin, higher hill) is a paired structure that is part of the Brain 's tectal area. In biological anatomy the mesencephalon (or midbrain) comprises the Tectum (or corpora quadrigemini Tegmentum, the ventricular mesocoelia (or "iter" A saccade is a fast movement of an eye, head or other part of an animal's body or device ^[9]

A final population of photosensitive ganglion cells, containing melanopsin, sends information via the retinohypothalamic tract (RHT) to the pretectum (pupillary reflex), to several structures involved in the control of circadian rhythms and sleep such as the suprachiasmatic nucleus (SCN, the biological clock), and to the ventrolateral preoptic nucleus (VLPO, a region involved in sleep regulation). Photosensitive ganglion cells, or melanopsin-containing ganglion cells, are a recently discovered type of nerve cell in the Retina of the mammalian Melanopsin is a Photopigment found in specialized Photosensitive ganglion cells of the Retina that are involved in the regulation of Circadian rhythms The Retinohypothalamic tract (RHT is a photic input pathway involved in Circadian rhythms. Pretectum is a structure located in the Midbrain. It receives binocular input from the Eyes and is involved with the pupillary light reflex. Sleep is a Natural state of bodily rest observed throughout the animal kingdom The suprachiasmatic nucleus ( SCN) is a bilateral region of the brain located in the Hypothalamus, that is responsible for controlling endogenous Circadian rhythms The ventrolateral preoptic nucleus (VLPO is a group of Neurons in the Hypothalamus. The ventrolateral preoptic nucleus (VLPO is a group of Neurons in the Hypothalamus. ^[10] A recently discovered role for photoreceptive ganglion cells is that they mediate conscious and unconscious vision - acting as rudimentary visual brightness detectors shown in rodless coneless eyes. ^[11]

Optic chiasm

Main article: Optic chiasm

The optic nerves from both eyes meet and cross at the optic chiasm, at the base of the hypothalamus of the brain. The optic chiasm ( Greek χίασμα "crossing" from the Greek χλαζειν 'to mark with an X' after the Greek letter ' Χ ' chi) is the The optic chiasm ( Greek χίασμα "crossing" from the Greek χλαζειν 'to mark with an X' after the Greek letter ' Χ ' chi) is the The hypothalamus links the Nervous system to the Endocrine system via the Pituitary gland (hypophysis At this point the information coming from both eyes is combined and then splits according to the visual field. The term visual field is sometimes used as a Synonym to Field of view, though they do not designate the same thing The corresponding halves of the field of view (right and left) are sent to the left and right halves of the brain, respectively, to be processed. That is, the right side of primary visual cortex deals with the left half of the field of view from both eyes, and similarly for the left brain. ^[9] A small region in the center of the field of view is processed redundantly by both halves of the brain.

Optic tract

Main article: Optic tract

Information from the right visual field (now on the left side of the brain) travels in the left optic tract. The optic tract is a part of the Visual system in the Brain. It is a continuation of the Optic nerve and runs from the Optic chiasm (where The optic tract is a part of the Visual system in the Brain. It is a continuation of the Optic nerve and runs from the Optic chiasm (where Information from the left visual field travels in the right optic tract. Each optic tract terminates in the lateral geniculate nucleus (LGN) in the thalamus. The lateral geniculate nucleus ( LGN) of the Thalamus is a part of the Brain, which is the primary processor of visual information received from the

Six layers in the LGN

Lateral geniculate nucleus

Main article: lateral geniculate nucleus

The lateral geniculate nucleus (LGN) is a sensory relay nucleus in the thalamus of the brain. The lateral geniculate nucleus ( LGN) of the Thalamus is a part of the Brain, which is the primary processor of visual information received from the The LGN consists of six layers in humans and other primates starting from catarhinians, including cercopithecidae and apes. Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus A primate is a member of the biological order Primates ( Latin: "prime first rank" the group that contains Lemurs the Aye-aye Layers 1, 4, and 6 correspond to information from the contralateral (crossed) fibers of the nasal visual field; layers 2, 3, and 5 correspond to information from the ipsilateral (uncrossed) fibers of the temporal visual field. Information as a concept has a diversity of meanings from everyday usage to technical settings Layer one (1) contains M cells, which correspond to the M (magnocellular) cells of the optic nerve of the opposite eye, and are concerned with depth or motion. Layers four and six (4 & 6) of the LGN also connect to the opposite eye, but to the P cells (color and edges) of the optic nerve. By contrast, layers two, three and five (2, 3, & 5) of the LGN connect to the M cells and P (parvocellular) cells of the optic nerve for the same side of the brain as its respective LGN. The six layers of the LGN are the area of a credit card, but about three times the thickness of a credit card, rolled up into two ellipsoids about the size and shape of two small birds eggs. A credit card is part of a system of Payments named after the small Plastic card issued to users of the system In between the six layers are smaller cells that receive information from the K cells (color) in the retina. The neurons of the LGN then relay the visual image to the primary visual cortex (V1) which is located at the back of the brain (caudal end) in the occipital lobe in and close to the calcarine sulcus. The term visual cortex refers to the primary visual cortex (also known as striate cortex or In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species The occipital lobe is the visual processing center of the Mammalian Brain containing most of the anatomical region of the Visual cortex.

Gray's FIG. Henry Gray's Anatomy of the Human Body (or Gray's Anatomy as it has commonly been shortened is an English-language Human anatomy Textbook 722– Scheme showing central connections of the optic nerves and optic tracts. The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain.

Optic radiation

Main article: Optic radiation

The optic radiations carries information from the thalamic lateral geniculate nucleus to layer 4 of the visual cortex. The optic radiation (also known as the geniculo-calcarine tract or as the geniculostriate pathway) is a collection of Axons from Relay neurons The lateral geniculate nucleus ( LGN) of the Thalamus is a part of the Brain, which is the primary processor of visual information received from the The term visual cortex refers to the primary visual cortex (also known as striate cortex or The P layer neurons of the LGN relay to V1 layer 4C β. The M layer neurons relay to V1 layer 4C α. The K layer neurons in the LGN relay to large neurons called blobs in layers 2 and 3 of V1.

There is a direct correspondence from an angular position in the field of view of the eye, all the way through the optic tract to a nerve position in V1. The field of view (also field of vision) is the angular extent of the observable world that is seen at any given moment Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain At this juncture in V1, the image path ceases to be straightforward; there is more cross-connection within the visual cortex.

Visual cortex

Main article: Visual cortex

Visual cortex: V1, V2, V3, V4, V5 (also called MT)

The visual cortex is the most massive system in the human brain and is responsible for higher-level processing of the visual image. The term visual cortex refers to the primary visual cortex (also known as striate cortex or The term visual cortex refers to the primary visual cortex (also known as striate cortex or The term visual cortex refers to the primary visual cortex (also known as striate cortex or It lies at the rear of the brain (highlighted in the image), above the cerebellum. The cerebellum ( Latin: "little brain" is a region of the Brain that plays an important role in the integration of sensory perception The interconnections between layers of the cortex, the thalamus, the cerebellum, the hippocampus and the remainder of the areas of the brain are under active investigation. The cerebral cortex is a structure within the Brain that plays a key role in Memory, Attention, perceptual Awareness, Thought, The hippocampus is a part of the Forebrain, located in the medial Temporal lobe. Currently, much of what is known stems from patients with damage to known areas of the brain, with a corresponding study of the cognitive functions which have been spared. See visual modularity for a discussion of the modular thesis of visual perception. In Cognitive neuroscience, visual modularity is an organizational concept concerning how vision works

See also

• Dorsal stream
• Echolocation
• Machine vision
• Memory-prediction framework
• Ventral stream
• Visual perception
• Visual modularity

References

• David H. Hubel (1989), Eye, Brain and Vision. David Hunter Hubel (born February 27, 1926) was co-recipient with Torsten Wiesel of the 1981 Nobel Prize in Physiology or Medicine, for their Year 1989 ( MCMLXXXIX) was a Common year starting on Sunday (link displays 1989 Gregorian calendar) New York: Scientific American Library.
• David Marr (1982), Vision: A Computational Investigation into the Human Representation and Processing of Visual Information. David Courtnay Marr ( January 19, 1945 - November 17, 1980) was a British Neuroscientist and Psychologist. Year 1982 ( MCMLXXXII) was a Common year starting on Friday (link displays the 1982 Gregorian calendar) San Francisco: W. H. Freeman.
• R. W. Rodiek (1988). "The Primate Retina". Comparative Primate Biology Vol. 4 of Neurosciences. (H. D. Steklis and J. Erwin, editors. ) pp. 203-278. New York: A. R. Liss.
• Matthew Schmolesky, The Primary Visual Cortex
• Martin J. Tovée (1996), An introduction to the visual system. Year 1996 ( MCMXCVI) was a Leap year starting on Monday (link will display full 1996 Gregorian calendar) Cambridge University Press, ISBN 0-521-48339-5 (References, pp. 180-198. Index, pp. 199-202. 202 pages. )
• Andreas Vesalius (1543) De Humani Corporis Fabrica (On the Workings of the Human Body)
• Torsten Wiesel and David H. Hubel (1963), "The effects of visual deprivation on the morphology and physiology of cell's lateral geniculate body". Andreas Vesalius ( Brussels, December 31, 1514 - Zakynthos, October 15, 1564) was an anatomist, Physician De humani corporis fabrica libri septem ( On the fabric of the human body in seven books) is a textbook of human anatomy written by Andreas Vesalius Torsten Nils Wiesel (b June 3, 1924) was a Swedish co-recipient with David H David Hunter Hubel (born February 27, 1926) was co-recipient with Torsten Wiesel of the 1981 Nobel Prize in Physiology or Medicine, for their Year 1963 ( MCMLXIII) was a Common year starting on Tuesday (link will display full calendar of the Gregorian calendar. Journal of Neurophysiology 26, 978-993.

External links

• "Webvision: The Organization of the Retina and Visual System" - John Moran Eye Center at University of Utah
• VisionScience.com - An online resource for researchers in vision science.
• Journal of Vision - An online, open access journal of vision science.
• Hagfish research has found the “missing link” in the evolution of the eye. See: Nature Reviews Neuroscience.