The document provides detailed information about the anatomy and physiology of the human eye. It includes labeled diagrams and descriptions of the major parts of the eye such as the cornea, iris, lens, retina, optic nerve and their functions. It also explains common eye conditions that can occur when certain parts are damaged or not functioning properly, such as cataracts, glaucoma and macular degeneration.
The aqueous humor is a thin, watery fluid located in the anterior chamber of the eye between the cornea and iris. It is produced by the ciliary body and nourishes the cornea and lens while maintaining the shape and intraocular pressure of the eye. The aqueous humor is composed primarily of water along with proteins, glucose, ions, ascorbate and other nutrients. It flows continuously from the ciliary body into the anterior chamber and exits through the trabecular meshwork. Glaucoma is caused by increased pressure from blocked aqueous humor flow. The vitreous humor is a clear gel located between the lens and retina that provides structure and contains few cells.
in this ppt we describe about anatomy of eyeball( cornea, sclera, choroid, iris, retina, ciliary body, vitreous etc..), dimension of the eyeball, coats of the eyeball.
structure of eye ball,eyeball is a specialized sense organ that helps us to understand our environment. It is a sensory unit composed of three parts: receptor, sensory pathway, and a brain center
The main parts of the human eye are The Conjunctiva,
Sclera,Choroid,
Cornea, Iris, Pupil,
Anterior Chamber,
Posterior Chamber, Aqueous humor, Lens, Vitreous humor, Retina,Macula and Optic nerve.
Tear film
1. TEAR FILM
2. The outer most layer of the cornea. It is the exposed part of the eyeball. FUNCTION It provide smooth optical surface It serves to keep the surface of cornea and conjunctiva moist. It serves as a lubricant for the preocular surface and lids It transfer oxygen from the air to the cornea Prevent infection due to the presence of antibacterial substance like lysozymes,and other protein. It wash away debris and irritants Provides pathway to WBC in case of injury.
3. LAYERS OF TEAR FILM It consist of three layers: 1.Lipid layer 2.Aqueous layer 3.Mucoid layer 1.LIPID LAYER
The tear film has three layers:
1. A mucin layer secreted by goblet cells that forms a hydrophilic barrier on the cornea.
2. An aqueous layer secreted mainly by the lacrimal gland, containing proteins, electrolytes, and other components.
3. An outer lipid layer secreted by meibomian glands that prevents evaporation and maintains tear film stability.
The tear film is regulated by hormonal and neural pathways and provides nutrients to the cornea, removes waste, lubricates the eye, and protects against infection through its biochemical composition.
The human eye is an organ that reacts to light in many circumstances. As a conscious sense organ, the human eye allows vision; rod and cone cells in the retina allow conscious light perception and vision, including color differentiation and the perception of depth. The human eye can distinguish about 10 million colors.
The retinal anatomy document summarizes the layers and structures of the retina. It notes that the retina consists of 10 distinct layers, including the retinal pigment epithelium, photoreceptor layer, and ganglion cell layer. It describes landmarks such as the macula lutea, fovea centralis, and optic disc. The document also discusses the blood supply to the retina from the central retinal artery and choroidal capillaries, as well as the neuroglial and neurotransmitter components of the retina.
The uvea is the middle vascular layer of the eyeball and consists of the iris, ciliary body, and choroid. The iris is a thin circular structure that forms the diaphragm in front of the lens and contains the pupil. The ciliary body is a ring-shaped structure that projects posteriorly from the scleral spur and contains ciliary processes that extend into the posterior chamber. The choroid is a highly vascular membrane that lines the inner surface of the sclera and extends from the ora serrata posteriorly.
The aqueous humor is a thin, watery fluid located in the anterior chamber of the eye between the cornea and iris. It is produced by the ciliary body and nourishes the cornea and lens while maintaining the shape and intraocular pressure of the eye. The aqueous humor is composed primarily of water along with proteins, glucose, ions, ascorbate and other nutrients. It flows continuously from the ciliary body into the anterior chamber and exits through the trabecular meshwork. Glaucoma is caused by increased pressure from blocked aqueous humor flow. The vitreous humor is a clear gel located between the lens and retina that provides structure and contains few cells.
in this ppt we describe about anatomy of eyeball( cornea, sclera, choroid, iris, retina, ciliary body, vitreous etc..), dimension of the eyeball, coats of the eyeball.
structure of eye ball,eyeball is a specialized sense organ that helps us to understand our environment. It is a sensory unit composed of three parts: receptor, sensory pathway, and a brain center
The main parts of the human eye are The Conjunctiva,
Sclera,Choroid,
Cornea, Iris, Pupil,
Anterior Chamber,
Posterior Chamber, Aqueous humor, Lens, Vitreous humor, Retina,Macula and Optic nerve.
Tear film
1. TEAR FILM
2. The outer most layer of the cornea. It is the exposed part of the eyeball. FUNCTION It provide smooth optical surface It serves to keep the surface of cornea and conjunctiva moist. It serves as a lubricant for the preocular surface and lids It transfer oxygen from the air to the cornea Prevent infection due to the presence of antibacterial substance like lysozymes,and other protein. It wash away debris and irritants Provides pathway to WBC in case of injury.
3. LAYERS OF TEAR FILM It consist of three layers: 1.Lipid layer 2.Aqueous layer 3.Mucoid layer 1.LIPID LAYER
The tear film has three layers:
1. A mucin layer secreted by goblet cells that forms a hydrophilic barrier on the cornea.
2. An aqueous layer secreted mainly by the lacrimal gland, containing proteins, electrolytes, and other components.
3. An outer lipid layer secreted by meibomian glands that prevents evaporation and maintains tear film stability.
The tear film is regulated by hormonal and neural pathways and provides nutrients to the cornea, removes waste, lubricates the eye, and protects against infection through its biochemical composition.
The human eye is an organ that reacts to light in many circumstances. As a conscious sense organ, the human eye allows vision; rod and cone cells in the retina allow conscious light perception and vision, including color differentiation and the perception of depth. The human eye can distinguish about 10 million colors.
The retinal anatomy document summarizes the layers and structures of the retina. It notes that the retina consists of 10 distinct layers, including the retinal pigment epithelium, photoreceptor layer, and ganglion cell layer. It describes landmarks such as the macula lutea, fovea centralis, and optic disc. The document also discusses the blood supply to the retina from the central retinal artery and choroidal capillaries, as well as the neuroglial and neurotransmitter components of the retina.
The uvea is the middle vascular layer of the eyeball and consists of the iris, ciliary body, and choroid. The iris is a thin circular structure that forms the diaphragm in front of the lens and contains the pupil. The ciliary body is a ring-shaped structure that projects posteriorly from the scleral spur and contains ciliary processes that extend into the posterior chamber. The choroid is a highly vascular membrane that lines the inner surface of the sclera and extends from the ora serrata posteriorly.
The document summarizes the physiology of aqueous humour in the eye. It is produced by the ciliary body at a rate of around 2.5 μL/min and has a similar composition to plasma but with lower protein levels. It is replenished around every 100 minutes. Aqueous humour maintains intraocular pressure and provides nutrients to ocular tissues before draining through the trabecular meshwork. Increased pressure can lead to glaucoma, which involves damage to the optic nerve and visual field loss. Diagnosis involves measuring pressure, examining the optic nerve and drainage angle, and testing vision.
The document describes the optical properties of the human eye. It compares the eye to a camera and describes the key optical elements like the cornea, lens, iris, and retina. It discusses the compound optical system of the eye and provides data on refractive indices and radii of curvature from Gullstrand's schematic eye model. It also describes reduced eye models proposed by Listing and Donders that simplify the eye's optics using single refractive surfaces and focal points.
This document discusses the extraocular muscles. It begins with an overview of the extraocular muscles and their nerve supply. It then provides more detailed information on the individual muscles, including their origin, insertion, blood supply, innervation and actions. It discusses concepts like Listing's law, Hering's law of equal innervation and Sherrington's law of reciprocal innervation. Clinical significance and applications to conditions like strabismus are also mentioned.
UVEA constitutes- middle vascular coat
• 3 parts- a)iris
b)ciliary body
c)choroid
• Developmentally,structurally and functionallyindivisible
• color varies from light blue to dark brown
EMBRYOLOGY
IRIS-
• Both layers of epithelium derived from
marginal region of optic cup (neuroectoderm)
• Sphincter and dilator pupillae- anterior
epithelium (neuroectoderm)
• Stroma and vessels- vascular mesoderm
The lacrimal apparatus is the physiological system containing the orbital structures for tear production and drainage. It consists of: The lacrimal gland, which secretes the tears, and its excretory ducts, which convey the fluid to the surface of the human eye;it is a serous gland located in lacrimal fossa.
This ppt file belongs to Mr. Yonas Akalu one of my best instructors ...
Vision is by far the most used of the five senses and is one of the primary means that we use to gather information from our surroundings. More than 75% of the information we receive about the world around us consists of visual information.
The eye is often compared to a camera. Each gathers light and then transforms that light into a "picture." Both also have lenses to focus the incoming light. Just as a camera focuses light onto the film to create a picture, the eye focuses light onto a specialized layer of cells, called the retina.
The human eye is an organ which reacts to light and pressure. As a sense organ, the mammalian eye allows vision. Human eyes help to provide a three dimensional, moving image, normally coloured in daylight. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth. The human eye can differentiate between about 10 million colors[1] and is possibly capable of detecting a single photon.
The document discusses the physiology of vision. It describes the main mechanisms of vision including light incidence, transduction, transmission of visual sensations, and visual perceptions. It then discusses the anatomy of the eye, including the cornea, lens, retina, and aberrations like spherical aberration. It also covers topics like accommodation, visual processing in the retina, visual pathway to the brain, and analysis in the primary and secondary visual cortices.
The eye consists of three coats - the fibrous outer coat containing the sclera and cornea, the vascular pigmented middle coat containing the choroid, ciliary body and iris, and the inner nervous coat containing the retina. The eyeball also contains refractive media - the aqueous humor in the anterior and posterior chambers, the vitreous body filling the vitreous chamber behind the lens, and the transparent biconvex lens situated between the iris and vitreous body. These structures work together to allow light to enter the eye and be focused on the retina to produce vision.
The human eye consists of eight main parts - the sclera, cornea, iris, pupil, choroid, crystalline lens, retina, and optic nerve. Light enters through the cornea and is focused by the lens onto the retina. The retina contains light-sensitive rod and cone cells that generate signals sent by the optic nerve to the brain, where they are interpreted as vision. Common vision defects include near-sightedness and far-sightedness, which can be corrected using concave or convex lenses, respectively.
This document summarizes the physiology of vision. It discusses:
1) How visual impulses are processed and transmitted from photoreceptors in the retina through the visual pathway to the visual cortex.
2) The types of cells involved in retinal processing and their functions, including rods, cones, horizontal cells, bipolar cells, amacrine cells and ganglion cells.
3) How visual signals are transmitted from the retina through the optic nerve, lateral geniculate body, and optic radiations to the primary visual cortex.
4) The layers and connections of the primary visual cortex and properties of simple, complex and hypercomplex cells in the visual cortex.
This document discusses the physiology of vision. It begins by describing the anatomy of the eyeball including its three layers - fibrous, vascular, and nervous layers. It then discusses the refractive errors of the eye like myopia, hyperopia, and presbyopia. The document explains how light enters the eye and is refracted to form an image on the retina. It also discusses accommodation, astigmatism, color vision and the visual pathway. In summary, the document provides an overview of the anatomy of the eye and the physiological processes underlying vision like refraction, accommodation, and transduction of light signals in the retina.
This document discusses the muscles of the eye. It describes two types of muscles: intraocular muscles that change the shape of the lens and size of the pupil, and extraocular muscles that control eye movement. The six extraocular muscles are identified along with their nerve supply, origin, insertion and actions. Diagrams illustrate the individual and coordinated movements of the eyes. Finally, some common disorders involving the eye muscles are listed.
The eyelids are composed of several layers including skin, muscle, orbital septum, fat and conjunctiva. The upper eyelid is raised by the levator palpebrae superioris muscle and Muller's muscle. The lower eyelid is retracted by the capsulopalpebral fascia. Several glands including the meibomian glands and glands of Zeis and Moll are located within the eyelids and help form the tear film. The orbicularis oculi muscle allows for eyelid closure and blinking. Together, the eyelid structures protect the eye and help spread tears across the surface of the eye.
The conjunctiva is a thin, semi-transparent mucous membrane that covers the inner surface of the eyelids and the outer surface of the sclera. It has three parts: the palpebral conjunctiva covers the inner eyelid, the forniceal conjunctiva is in the eyelid folds, and the bulbar conjunctiva covers the eyeball. The conjunctiva contains goblet cells that secrete mucus and has blood vessels for nutrition and lymphatic drainage. It helps maintain the tear film and prevents microbes from entering the eye.
The uvea consists of the iris, ciliary body, and choroid. It develops from both neuroectoderm and vascular mesoderm. The iris develops fully by age 5, with pigmentation continuing after birth. The ciliary body appears by 9 weeks and is fully developed by 6 months gestation. The choroid layers are seen by 5 months gestation. The uvea regulates light entry and provides blood supply to the outer retina. Congenital anomalies include heterochromia, polycoria, persistent pupillary membranes, and colobomas. Uveitis is inflammation of the uveal tract.
The document discusses the three coats of the eye:
1. The outer coat is called the fibrous tunic and is composed of the sclera and cornea. The sclera covers most of the eyeball and provides structural support, while the cornea allows light to enter.
2. The middle coat is the vascular tunic, also called the uvea. It contains the choroid, ciliary body, and iris. The choroid supplies blood vessels and nutrients to the eye, while the ciliary body anchors the lens and controls accommodation.
3. The innermost coat is the retina, which contains light-sensitive cells called rods and cones that are responsible for vision.
The eye is made up of three coats - fibrous, vascular and nervous. The fibrous coat includes the sclera and cornea. The vascular coat provides nutrition via the uveal tract. The nervous coat is the retina which senses light. Within the eyeball are two chambers filled with aqueous humor - the anterior chamber between the cornea and iris and the posterior chamber between the iris and lens. The iris controls the size of the pupil to regulate light. The choroid nourishes the retina and the lens focuses light onto the retina to be transmitted to the brain via the optic nerve.
This document describes the anatomy and biochemistry of various components of the eye. It discusses the cornea, lens, vitreous humour, aqueous humour, retina and tear film. The cornea consists of five layers and is mostly water. The lens is a transparent biconvex structure behind the iris that is high in water and proteins. The vitreous humour is a gel-like fluid behind the lens composed mainly of water, collagen and carbohydrates. The aqueous humour maintains intraocular pressure and contains mostly water and small amounts of protein. The retina converts light signals into nerve signals that are sent to the brain via the optic nerve.
The tear film constitutes Three layers :- An outermost lipid (oily) layer An aqueous (watery) layer that makes up 90% of the tear film volume; and A mucin layer that coats the corneal surface.
3. To form smooth optical surface on cornea. To keep the surface of cornea & conjunctiva moist It serve as lubricant It transfer oxygen Provide antibacterial action Wash debris out It provides a pathway for WBC in case of injury
4. Functions of lipid layer Retards evaporation of tear film Prevents the overflow of tears
5. Function of Aqueous Layer Flushes, buffers and lubricates the corneal surface Delivers oxygen and other nutrients to the corneal surface Wash out debris Delivers antibacterial enzymes and antibodies such as lysozyme.
6. Functions of Mucin Layer Spreads tears over corneal surface. Protects the cornea against foreign substances . Makes corneal surface smooth by filling in surface irregularities
The document summarizes the anatomy and physiology of the retina. It describes the three main regions of the retina - optic disc, macula lutea, and peripheral retina. It details the microscopic layers of the retina and the cells within each layer. It discusses the visual pigments rhodopsin and cone pigments, and how light induces photochemical changes in these pigments to initiate the visual process. Finally, it briefly outlines the pathway of visual signal transmission from the retina to the visual cortex.
he sense organs — eyes, ears, tongue, skin, and nose — help to protect the body. The human sense organs contain receptors that relay information through sensory neurons to the appropriate places within the nervous system.
Each sense organ contains different receptors.
General receptors are found throughout the body because they are present in skin, visceral organs (visceral meaning in the abdominal cavity), muscles, and joints.
Special receptors include chemoreceptors (chemical receptors) found in the mouth and nose, photoreceptors (light receptors) found in the eyes, and mechanoreceptors found in the ears.
The document describes the anatomy and functions of the human eye. It explains that light enters the eye and is focused by the cornea and lens onto the retina. The retina contains light-sensitive cells that convert the image to neural signals sent to the brain via the optic nerve. It also provides details on common eye conditions like cataracts and pink eye, as well as comparisons between human and cow eye anatomy.
The document summarizes the physiology of aqueous humour in the eye. It is produced by the ciliary body at a rate of around 2.5 μL/min and has a similar composition to plasma but with lower protein levels. It is replenished around every 100 minutes. Aqueous humour maintains intraocular pressure and provides nutrients to ocular tissues before draining through the trabecular meshwork. Increased pressure can lead to glaucoma, which involves damage to the optic nerve and visual field loss. Diagnosis involves measuring pressure, examining the optic nerve and drainage angle, and testing vision.
The document describes the optical properties of the human eye. It compares the eye to a camera and describes the key optical elements like the cornea, lens, iris, and retina. It discusses the compound optical system of the eye and provides data on refractive indices and radii of curvature from Gullstrand's schematic eye model. It also describes reduced eye models proposed by Listing and Donders that simplify the eye's optics using single refractive surfaces and focal points.
This document discusses the extraocular muscles. It begins with an overview of the extraocular muscles and their nerve supply. It then provides more detailed information on the individual muscles, including their origin, insertion, blood supply, innervation and actions. It discusses concepts like Listing's law, Hering's law of equal innervation and Sherrington's law of reciprocal innervation. Clinical significance and applications to conditions like strabismus are also mentioned.
UVEA constitutes- middle vascular coat
• 3 parts- a)iris
b)ciliary body
c)choroid
• Developmentally,structurally and functionallyindivisible
• color varies from light blue to dark brown
EMBRYOLOGY
IRIS-
• Both layers of epithelium derived from
marginal region of optic cup (neuroectoderm)
• Sphincter and dilator pupillae- anterior
epithelium (neuroectoderm)
• Stroma and vessels- vascular mesoderm
The lacrimal apparatus is the physiological system containing the orbital structures for tear production and drainage. It consists of: The lacrimal gland, which secretes the tears, and its excretory ducts, which convey the fluid to the surface of the human eye;it is a serous gland located in lacrimal fossa.
This ppt file belongs to Mr. Yonas Akalu one of my best instructors ...
Vision is by far the most used of the five senses and is one of the primary means that we use to gather information from our surroundings. More than 75% of the information we receive about the world around us consists of visual information.
The eye is often compared to a camera. Each gathers light and then transforms that light into a "picture." Both also have lenses to focus the incoming light. Just as a camera focuses light onto the film to create a picture, the eye focuses light onto a specialized layer of cells, called the retina.
The human eye is an organ which reacts to light and pressure. As a sense organ, the mammalian eye allows vision. Human eyes help to provide a three dimensional, moving image, normally coloured in daylight. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth. The human eye can differentiate between about 10 million colors[1] and is possibly capable of detecting a single photon.
The document discusses the physiology of vision. It describes the main mechanisms of vision including light incidence, transduction, transmission of visual sensations, and visual perceptions. It then discusses the anatomy of the eye, including the cornea, lens, retina, and aberrations like spherical aberration. It also covers topics like accommodation, visual processing in the retina, visual pathway to the brain, and analysis in the primary and secondary visual cortices.
The eye consists of three coats - the fibrous outer coat containing the sclera and cornea, the vascular pigmented middle coat containing the choroid, ciliary body and iris, and the inner nervous coat containing the retina. The eyeball also contains refractive media - the aqueous humor in the anterior and posterior chambers, the vitreous body filling the vitreous chamber behind the lens, and the transparent biconvex lens situated between the iris and vitreous body. These structures work together to allow light to enter the eye and be focused on the retina to produce vision.
The human eye consists of eight main parts - the sclera, cornea, iris, pupil, choroid, crystalline lens, retina, and optic nerve. Light enters through the cornea and is focused by the lens onto the retina. The retina contains light-sensitive rod and cone cells that generate signals sent by the optic nerve to the brain, where they are interpreted as vision. Common vision defects include near-sightedness and far-sightedness, which can be corrected using concave or convex lenses, respectively.
This document summarizes the physiology of vision. It discusses:
1) How visual impulses are processed and transmitted from photoreceptors in the retina through the visual pathway to the visual cortex.
2) The types of cells involved in retinal processing and their functions, including rods, cones, horizontal cells, bipolar cells, amacrine cells and ganglion cells.
3) How visual signals are transmitted from the retina through the optic nerve, lateral geniculate body, and optic radiations to the primary visual cortex.
4) The layers and connections of the primary visual cortex and properties of simple, complex and hypercomplex cells in the visual cortex.
This document discusses the physiology of vision. It begins by describing the anatomy of the eyeball including its three layers - fibrous, vascular, and nervous layers. It then discusses the refractive errors of the eye like myopia, hyperopia, and presbyopia. The document explains how light enters the eye and is refracted to form an image on the retina. It also discusses accommodation, astigmatism, color vision and the visual pathway. In summary, the document provides an overview of the anatomy of the eye and the physiological processes underlying vision like refraction, accommodation, and transduction of light signals in the retina.
This document discusses the muscles of the eye. It describes two types of muscles: intraocular muscles that change the shape of the lens and size of the pupil, and extraocular muscles that control eye movement. The six extraocular muscles are identified along with their nerve supply, origin, insertion and actions. Diagrams illustrate the individual and coordinated movements of the eyes. Finally, some common disorders involving the eye muscles are listed.
The eyelids are composed of several layers including skin, muscle, orbital septum, fat and conjunctiva. The upper eyelid is raised by the levator palpebrae superioris muscle and Muller's muscle. The lower eyelid is retracted by the capsulopalpebral fascia. Several glands including the meibomian glands and glands of Zeis and Moll are located within the eyelids and help form the tear film. The orbicularis oculi muscle allows for eyelid closure and blinking. Together, the eyelid structures protect the eye and help spread tears across the surface of the eye.
The conjunctiva is a thin, semi-transparent mucous membrane that covers the inner surface of the eyelids and the outer surface of the sclera. It has three parts: the palpebral conjunctiva covers the inner eyelid, the forniceal conjunctiva is in the eyelid folds, and the bulbar conjunctiva covers the eyeball. The conjunctiva contains goblet cells that secrete mucus and has blood vessels for nutrition and lymphatic drainage. It helps maintain the tear film and prevents microbes from entering the eye.
The uvea consists of the iris, ciliary body, and choroid. It develops from both neuroectoderm and vascular mesoderm. The iris develops fully by age 5, with pigmentation continuing after birth. The ciliary body appears by 9 weeks and is fully developed by 6 months gestation. The choroid layers are seen by 5 months gestation. The uvea regulates light entry and provides blood supply to the outer retina. Congenital anomalies include heterochromia, polycoria, persistent pupillary membranes, and colobomas. Uveitis is inflammation of the uveal tract.
The document discusses the three coats of the eye:
1. The outer coat is called the fibrous tunic and is composed of the sclera and cornea. The sclera covers most of the eyeball and provides structural support, while the cornea allows light to enter.
2. The middle coat is the vascular tunic, also called the uvea. It contains the choroid, ciliary body, and iris. The choroid supplies blood vessels and nutrients to the eye, while the ciliary body anchors the lens and controls accommodation.
3. The innermost coat is the retina, which contains light-sensitive cells called rods and cones that are responsible for vision.
The eye is made up of three coats - fibrous, vascular and nervous. The fibrous coat includes the sclera and cornea. The vascular coat provides nutrition via the uveal tract. The nervous coat is the retina which senses light. Within the eyeball are two chambers filled with aqueous humor - the anterior chamber between the cornea and iris and the posterior chamber between the iris and lens. The iris controls the size of the pupil to regulate light. The choroid nourishes the retina and the lens focuses light onto the retina to be transmitted to the brain via the optic nerve.
This document describes the anatomy and biochemistry of various components of the eye. It discusses the cornea, lens, vitreous humour, aqueous humour, retina and tear film. The cornea consists of five layers and is mostly water. The lens is a transparent biconvex structure behind the iris that is high in water and proteins. The vitreous humour is a gel-like fluid behind the lens composed mainly of water, collagen and carbohydrates. The aqueous humour maintains intraocular pressure and contains mostly water and small amounts of protein. The retina converts light signals into nerve signals that are sent to the brain via the optic nerve.
The tear film constitutes Three layers :- An outermost lipid (oily) layer An aqueous (watery) layer that makes up 90% of the tear film volume; and A mucin layer that coats the corneal surface.
3. To form smooth optical surface on cornea. To keep the surface of cornea & conjunctiva moist It serve as lubricant It transfer oxygen Provide antibacterial action Wash debris out It provides a pathway for WBC in case of injury
4. Functions of lipid layer Retards evaporation of tear film Prevents the overflow of tears
5. Function of Aqueous Layer Flushes, buffers and lubricates the corneal surface Delivers oxygen and other nutrients to the corneal surface Wash out debris Delivers antibacterial enzymes and antibodies such as lysozyme.
6. Functions of Mucin Layer Spreads tears over corneal surface. Protects the cornea against foreign substances . Makes corneal surface smooth by filling in surface irregularities
The document summarizes the anatomy and physiology of the retina. It describes the three main regions of the retina - optic disc, macula lutea, and peripheral retina. It details the microscopic layers of the retina and the cells within each layer. It discusses the visual pigments rhodopsin and cone pigments, and how light induces photochemical changes in these pigments to initiate the visual process. Finally, it briefly outlines the pathway of visual signal transmission from the retina to the visual cortex.
he sense organs — eyes, ears, tongue, skin, and nose — help to protect the body. The human sense organs contain receptors that relay information through sensory neurons to the appropriate places within the nervous system.
Each sense organ contains different receptors.
General receptors are found throughout the body because they are present in skin, visceral organs (visceral meaning in the abdominal cavity), muscles, and joints.
Special receptors include chemoreceptors (chemical receptors) found in the mouth and nose, photoreceptors (light receptors) found in the eyes, and mechanoreceptors found in the ears.
The document describes the anatomy and functions of the human eye. It explains that light enters the eye and is focused by the cornea and lens onto the retina. The retina contains light-sensitive cells that convert the image to neural signals sent to the brain via the optic nerve. It also provides details on common eye conditions like cataracts and pink eye, as well as comparisons between human and cow eye anatomy.
The human eye is a complex organ that enables vision. Light enters through the cornea and lens, and is focused onto the retina. The retina contains light-sensitive cells that convert the image into neural signals via the optic nerve. These signals are transmitted to the brain and interpreted as sight. The eye is well-protected by eyelids, tear glands, muscles, and its position in the skull.
The human eye is an organ that reacts to light in many circumstances. As a conscious sense organ the human eye allows vision; rod and cone cells in the retina allow conscious light perception and vision, including color differentiation and the perception of depth. The human eye can distinguish about 10 million colors.
The document summarizes the structure and function of the human eye. It describes the three layers that make up the eyeball - fibrous, vascular and nervous layers. The fibrous layer includes the sclera and cornea. The vascular layer includes the choroid, ciliary body and iris. The nervous layer is the retina. It also explains key parts of the eye like the iris, lens, vitreous humor and aqueous humor. The retina contains photoreceptors that convert light to neural signals sent to the brain via the optic nerve. The visual pathway and common refractive errors are also summarized.
The cornea is the clear dome-shaped surface at the front of the eye that acts as the first and most powerful lens in the optical system. It contains no blood vessels and relies on tears and fluid behind it to stay nourished. The pupil is a hole in the center of the iris that controls the amount of light entering the eye. The retina converts light rays into electrical signals that are sent to the brain through the optic nerve and is responsible for vision and color vision. Common eye problems include cataracts, which are clouded lenses, glaucoma which damages the optic nerve from pressure, and retinal disorders which affect the nerve layer at the back of the eye.
The document provides information about the anatomy and physiology of the eye. It describes the key structures of the eye including the eyelids, conjunctiva, cornea, iris, crystalline lens, vitreous, retina, optic nerve, and extraocular muscles. It explains the functions of these structures and how together they allow for vision. The tear film and its three layers that protect and nourish the eye are also discussed. The document provides a detailed yet easy to understand overview of the anatomy and physiology of the eye.
The eye contains three layers - outer fibrous layer, middle vascular layer, and inner nervous tissue layer. Light enters through the cornea and pupil, and is focused by the lens onto the retina. The retina converts light into electrical signals which are transmitted by the optic nerve to the brain. Muscles attached to the iris control the size of the pupil to regulate the amount of light entering the eye.
The document summarizes the anatomy and physiology of the human eye and visual system. It describes the five main parts of the eye: the outer fibrous layer containing the sclera and cornea, the middle vascular layer containing the choroid, ciliary body and iris, the inner nervous layer containing the retina, and interior structures like the lens. It also discusses the accessory structures that support vision like the extraocular muscles, eyebrows, eyelids, conjunctiva and lacrimal apparatus. The visual system converts light stimuli to nerve impulses via specialized photoreceptor cells in the retina that are transmitted to the brain via the optic nerve.
The eye is our organ of sight. The eye has a number of components which include but are not limited to the cornea, iris, pupil, lens, retina, macula, optic nerve, choroid and vitreous.
VISION IN ANIMALS VETERINARY PHYSIOLOGY.pdfTatendaMageja
This document provides an overview of canine vision anatomy and physiology. It describes the key structures of the eye, including the retina, iris, lens, cornea, and optic nerve. It explains how light enters the eye and is detected by photoreceptors in the retina. The visual signals are then transmitted through the retina and optic nerve to the brain for processing. Features like the pupil, lens curvature, and presence of the fovea centralis in some species enhance vision. The document also discusses conditions like Horner's syndrome that can affect the eye's function.
The document discusses the five sensory organs of the human body - eye, ear, nose, tongue, and skin. It focuses on providing details about the structure and function of the eye. The eye is made up of three layers - the outer fibrous layer, middle vascular layer, and inner layer. It describes the various parts of the eye like the iris, pupil, lens, retina and discusses how vision occurs when light enters the eye and signals are transmitted to the brain via the optic nerve. The document also briefly mentions common eye disorders and the physiology of vision.
SHAHID KHAN AZMI.organ of vision and pathway of vision.pptsk2023765
The eye is the main organ of vision. Light enters through the cornea and pupil and is focused by the lens onto the retina. The retina converts the light into neural signals which are transmitted through the optic nerve to the visual cortex of the brain, where an image is formed. The eye contains several parts including the iris, ciliary body, retina, sclera, choroid and optic nerve. Nutrients like vitamins A, C, lutein and zeaxanthin obtained from foods help support eye health and protect against vision problems.
structure and fuction of eyes and ears,types of memory,sharpe memory,attentionUmarKhan422
The document discusses the structure and function of the eye and ear and their importance in daily life. It provides detailed descriptions of the main parts of the eye including the cornea, iris, lens, retina, etc. and explains their functions. It also discusses the main parts of the ear like the outer, middle and inner ear and how they work together to detect and transmit sound to the brain. Finally, it outlines several important uses of vision and hearing in daily life like communication, enjoyment, safety and more and emphasizes the importance of managing hearing loss.
The document discusses the anatomy of the eye, including the outer layers like the sclera and cornea, middle layers such as the iris and choroid, and inner retinal layer. It also explains how light enters the eye and is processed, normal vision versus problems like astigmatism and blindness, and the causes and treatments of common vision issues such as cataracts and glaucoma. Color vision is enabled by the three types of cone pigments that are sensitive to different wavelengths of light.
The cornea is the clear dome-shaped surface at the front of the eye that acts as the first lens. Light passes through the pupil, which is controlled by the iris, and hits the retina where it is converted to electrical signals sent to the brain. The lens, located behind the iris, changes shape to focus light onto the retina. Common eye disorders include cataracts, which cloud the lens; glaucoma caused by increased fluid pressure damaging the optic nerve; and retinal disorders affecting the light-sensitive tissue at the back of the eye.
The eye is composed of three layers - the fibrous tunic, vascular tunic, and retina. The fibrous tunic includes the sclera and transparent cornea. The vascular tunic contains the choroid, ciliary body, and iris. The retina lines the inside of the eye and contains light-sensitive rod and cone cells. Light passes through the cornea and lens and strikes the retina, where it is converted to nerve signals sent to the brain via the optic nerve. The iris controls the size of the pupil to regulate light entry. Various structures work together to focus light and maintain the eye's shape and pressure.
The document describes the anatomy and physiology of the human eye. It details the structures of the eye including the fibrous layer (sclera and cornea), vascular layer (choroid, ciliary body, and iris), and sensory layer (retina containing rods and cones). It explains how light enters the eye and is refracted by the cornea, aqueous humor, lens, and vitreous humor, forming an inverted image on the retina. The ability of the lens to change shape and focus light on near and far objects through accommodation is also described. Common eye conditions like cataracts, glaucoma, and refractive errors are summarized.
The document describes the anatomy and physiology of the human eye. It details the structures of the eye including the fibrous layer with the sclera and cornea, the vascular layer with the choroid, ciliary body and iris, and the sensory layer with rods and cones in the retina. It explains how light enters the eye and is refracted by the cornea, aqueous humor, lens, and vitreous humor, forming an inverted image on the retina. The document also discusses common vision conditions like cataracts, glaucoma, color blindness, accommodation, and myopia.
This document discusses metabolic disorders involving proteins, amino acids, carbohydrates, and lipids. It provides details on various inborn errors of metabolism including phenylketonuria caused by phenylalanine hydroxylase deficiency, maple syrup urine disease caused by branched-chain ketoacid dehydrogenase deficiency, and glycogen storage diseases such as von Gierke's disease caused by glucose-6-phosphatase deficiency. It also discusses lipid metabolism disorders including carnitine deficiency and peroxisomal disorders like Zellweger syndrome. The document serves as a reference for inborn errors of metabolism and their associated enzymatic defects.
This document discusses various metabolic disorders related to proteins, amino acids, carbohydrates, and lipids. It provides details on specific enzyme defects and the resulting metabolic conditions, such as phenylketonuria from a defect in phenylalanine hydroxylase, maple syrup urine disease from defects in branched-chain alpha-keto acid dehydrogenase, and glycogen storage diseases like von Gierke's disease and Pompe's disease due to defects in glucose metabolism enzymes. The document also summarizes lipid metabolism disorders including defects in fatty acid beta-oxidation leading to conditions like infant death syndrome.
This lab examines cardiovascular and respiratory variables like heart sounds and blood pressure. Students will listen to their partner's heart sounds at different areas of the chest to identify the four major sounds. They will also measure their partner's blood pressure using both palpation and auscultation methods at rest and while changing positions to observe postural effects. The document provides background on heart sounds, blood pressure components, and procedures for accurately measuring blood pressure.
The endocrine system is made up of glands that secrete hormones directly into the bloodstream to regulate bodily functions. The major glands include the pituitary, thyroid, parathyroid, adrenal, pancreas and reproductive glands. Hormones regulate metabolism, growth and development, tissue function, sexual function, pregnancy and lactation. Gland secretions are regulated by feedback mechanisms involving the hypothalamus and pituitary. The endocrine system maintains homeostasis through synthesis and secretion of hormones which target distant organs and cells.
The document discusses regulations around Ayurvedic, Siddha, and Unani drugs in India. It establishes two advisory boards - the Ayurvedic, Siddha and Unani Drugs Technical Advisory Board and the Ayurvedic, Siddha and Unani Drugs Consultative Committee - to provide guidance around these traditional medicines. It also defines what makes these drugs misbranded, adulterated, or spurious and prohibits their manufacture or sale if these conditions are met. Licenses are required for their manufacture and the government can prohibit drugs deemed risky to public health.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
1. Drawings of the Eye
Cross section drawing of the eye - (side view) with major parts labeled.
Cross section drawing of the eye - (rear view).
2. Cut-away view of the eye in its socket showing the: bony socket, orbital muscles, eyelids and
eyelashes.
The lacrimal system - (tear ducts) produce tears to clean, moisten and lubricate the eyes and then
drains the excess fluid into the nose.
Our Eyes and brain divide what we see into a right and left half. In the drawing above, light gray
represents the left half; dark gray represents the right half. The eyes invert the image and the left
3. side of what we see ends up in the right side of our brain and visa versa. This all works out
because the right side of our brain controls the left side of our bodies and visa versa.
Anterior Chamber
The space between the cornea and iris filled with Aqueous Humor.
Aqueous Humor
A water like fluid, produced by the ciliary body, it fills the front of the eye
between the lens and cornea and provides the cornea and lens with oxygen and
nutrients. It drains back into the blood stream through the canals of schlemm.
Brain
The brain is where the electrical signals sent from our eyes are processed into
vision. Damage to the brain can lead to vision loss if the visual cortex or optic
pathways are damaged. The majority of nerve fibers in the optic tract connect
to the LGN. Several nerve fibers leave the optic tract before the LGN to
connect to sub cortical structures through out the brain. These parts of the brain
regulate things like: eye and head movements, pupillary light reflex - (pupil
size), and circadian rhythms - (light/dark cycle). Damage to these parts of the
brain often leads to vision disorders too.
Canals of Schlemm
These canals are located around the perimeter of the iris. They allow aqueous
fluid to drain back into the blood stream. The Trabecular Meshwork along with
the Canals of Schlemm regulate the eyes internal pressure. In the eye disease
called glaucoma, these canals become blocked leading to increased pressure.
The increased pressure, from this condition, destroys the optic nerve.
Choroid
The choroid is a layer of blood vessels between the retina and sclera; it supplies
blood to the retina. In the disease called Macular Degeneration, abnormal blood
vessels grow into the space between the retina and choroid damaging the
macula.
Ciliary Body
This is where the Aqueous Humor is produced.
Ciliary Muscle
The eye can bring the fine print in a phone book into focus, or focus in on the
moon over ¼ million miles away. The ciliary muscle changes the shape of the
lens - (this is called accommodation). It relaxes to flatten the lens for distance
vision; for close work it contracts rounding out the lens. Everyone will develop
an eye condition called presbyopia. As we age, the ciliary muscle and
crystalline lens lose their elasticity. This is why most people need reading
glasses by their 40's.
Conjunctiva
The conjunctiva is a thin, clear membrane covering the front of the eye and
inner eyelids. Cells in this lining produce mucous that helps to lubricate the
4. eye. This is the eyes first layer of protection against infection. Inflammation of
this membrane is called conjunctivitis, or pink eye.
Cornea
The cornea is a clear, dome-shaped surface that covers the front of the eye. It is
the first and most powerful lens in the eye's optical system. To keep it
transparent the cornea contains no blood vessels. Tears that flow over it and
aqueous humor in the chamber behind it keep it nourished. When you hear of
eye banks and eye transplants, it is the cornea that is being replaced. The cornea
can be damaged from: accidents, infections, and genetic defects.
Crystalline Lens
The eye's crystalline lens works like the adjustable lens in a camera. Positioned
just behind the cornea; it is responsible for keeping images in focus on the
retina. It is adjustable for distance and close work. A cataract is the lens
clouding up. This happens to most people as they age. A few people are even
born with cataracts. Modern surgery has all but eliminated cataracts as a cause
of blindness in the developed world.
Eyeball
The eye is like a little video camera measuring about 1 inch or 2.5 cm. in
diameter. If someone's eyeball is larger then this, they will be nearsighted
(myopic); if it is smaller then this, they will be farsighted (hyperopic). Having
two eyes gives us binocular vision - (depth perception). This is due to the
fusing of both images in the visual cortex.
Eyelashes and Eyebrows
These specialized hairs protect the eyes from particles that may injure them.
They form a screen to keep dust and insects out. Anything touching them
triggers the eyelids to blink.
Eyelids
Our eyelids protect and lubricate our eyes. Small oil-producing glands line the
inner edge of our eyelids. These oils mix with tears when we blink, keeping the
eye moist and clean.
Eye Socket
The orbit or eye socket is a cone-shaped bony cavity that protects the eye. The
socket is padded with fatty tissue that allows the eye to move easily.
Fovea - (small pit)
The fovea is an indentation in the center of the macula. Its diameter is only 1.5
mm or about 1/16 inch. This small part of our retina is responsible for our
highest visual acuity. It is the center of our central vision.
Lacrimal Gland - (Tear Duct)
This gland continually releases tears and other protective fluids onto the surface
of the eye. It lubricates and keeps the cornea from becoming dehydrated.
Lacrimal Sac
5. The lacrimal sac is a tiny pump that drains tears and other debris from the eye.
The fluids flow down the nasolacrimal duct into the nose where they help keep
the nasal linings moist. This is why your nose runs when you cry.
Lateral Geniculate Nucleus - (LGN)
This part of the brain acts as a relay station; it decodes visual information from
the optic tract before sending it to the visual cortex for final processing.
Lens Sack or Capsule
During modern cataract surgery the outer membrane of the lens is left in place.
The artificial intraocular lens is placed in this sack.
Iris
This is the colored part of the eye: brown, green, blue, etc. It is a ring of muscle
fibers located behind the cornea and in front of the lens. It contracts and
expands, opening and closing the pupil, in response to the brightness of
surrounding light. Just as the aperture in a camera protects the film from over
exposure, the iris of the eye helps protect the sensitive retina.
Macula - (yellow spot)
This part of the retina is the most sensitive. Its diameter is only 7 mm or about
1/4 inch. It is responsible for our central, or reading vision. This part of the
retina gives us 20/20 vision. Without the macula, you would be blind - Legally
Blind that is. People with eye diseases like Macular Degeneration have vision
from 20/200 to 20/800.
Optic Chiasm
This is the first part of the brain to receive visual input. Each eye takes a
slightly different picture of the world. At the optic chiasm each picture is
divided in half. The outer left and right halves continue back toward the visual
cortex. The inner left and right halves cross over to the other side of the brain
then continue back toward the visual cortex. See Drawing of optic pathways.
Optic Disk
The optic disk is the spot on the retina where the optic nerve leaves the eye.
There are no sensory cells here, creating a blind spot. Each eye covers for the
blind spot of the other eye and the brain fills in the missing information.
Optic Nerve
Each optic nerve has about 1.2 million nerve fibers. This is the cable
connecting the eye to the brain.
Optic Tract
The nerves that connect the optic chiasm to the LGN are called the optic tract.
If one of these tracts is damaged, vision will be lost in one side of each eye.
Orbital Muscles
Six muscles are in charge of eye movement. Four of these move the eye up,
down, left and right. The other two control the twisting motion of the eye when
we tilt our head. Defects in these muscles and the nerves that control them lead
to conditions like Nystagmus and Amblyopia (Lazy Eye).
6. Photoreceptor Cells
The retina is composed of two types of photoreceptor cells. When light falls on
one of these cells, it causes a chemical reaction that sends an electrical signal to
the brain.
Cone cells give us our detailed color daytime vision. There are 6 million of
them in each human eye. Most of them are located in the central retina - macula
fovea area. There are three types of cone cells: one sensitive to red light,
another to green light, and the third sensitive to blue light.
Rod cells are about 500 times more sensitive to light then cone cells; they give
us our dim light or night vision. They are also more sensitive to motion then
cone cells. There are 120 million rod cells in the human eye. Most rod cells are
located in our peripheral or side vision.
Posterior Chamber
The space between the iris and the front of the lens filled with Aqueous Humor.
Pupil
The pupil is the hole in the center of the iris that light passes through. The iris
muscles control its size.
Retina
The retina is the film of the eye. It converts light rays into electrical signals and
sends them to the brain through the optic nerve. The sides of the retina are
responsible for our peripheral vision. The center area, called the macula, is used
for our fine central vision and color vision. The retina is where most the
problems leading to vision loss Occur. Three of the leading causes of blindness,
from retina damage, are Retinitis Pigmentosa, Macular Degeneration and
Diabetic Retinopathy.
Retinal Blood Vessels
A doctor can see the blood vessels that supply the retina when he looks into
your eyes. These vessels are in the choroid just beneath the retina. Abnormal
blood vessel growth and leaking blood vessels are the cause of vision loss in
eye conditions like, Diabetic Retinopathy, ROP, and Macular Degeneration.
Retinal Pigment Epithelium - (RPE)
The RPE is a layer of cells between the retina and choroid. The inside of a
camera is panted black to absorb scattered and reflected light. The black
pigment known as melanin in the RPE dose the same job for the eye. The RPE
gets rid of waste products produced by the photoreceptor cells. As we age, the
RPE can sometimes lose its ability to process this waste. Deposits of this waste,
called drusen, can distort and damage the retina leading to an eye condition
called dry macular degeneration.
Sclera
The sclera is the white, tough wall of the eye. It along with internal fluid
pressure keeps the eyes shape and protects its delicate internal parts.
Uvea
7. The uvea is the middle Vascular layer of the eye. It is made up of three parts:
the iris, ciliary body and chorid. Uveitis is the inflammation (or swelling) of
these parts of the eye.
Visual Axis
The Visual Axis is an imaginary line drawn through the center of the pupil to
the center of the Fovea. The orbital muscles keep the visual axis of both eyes
aligned on the center of what you are looking at (fixation point). An eye
condition called Strabismus - (misaligned eyes) results when the orbital
muscles fail to keep the eyes in alignment. Any damage to eye structures along
this axis leads to severe vision loss.
Visual Cortex
The part of the brain that processes and combines visual information from both
eyes and converts it into sight. Damage to the visual cortex results in a
condition called cortical blindness.
Visual Fields
The retina of each eye has two sections the nasal retina - (nose side) and
temporal retina - (ear side). For example: with your right eye, you see the right
half of the world with your nasal retina; you see the left half of the world with
your temporal retina. The picture your eye takes is flipped left for right and
upside down; its up to the brain to sort things out.
Vitreous Cavity
The space between the lens and retina filled with the gel like Vitreous Humor.
Vitreous Humor
The vitreous humor is a jelly like liquid that fills most of the eye (from the lens
back). As we age it changes from a gel to a liquid and gradually shrinks
separating from the retina. This is when people start seeing floaters, dark specs
in their vision. This is a normal sign of aging, but in a few cases the retina can
become detached as the vitreous separates.
Zonules
Zonules are hundreds of string like fibers that hold the lens suspended in
position and enable it to change shape for near or distant vision.
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