The Anatomy And Physiology Of The Eye

Gibson’s and Gregory’s theories of perception both suggest that eye-retina is important for perception. The both believe that without eye-retina, a person will not be able to see. This is a common view of both of the theories of perception. The idea is supported by the case of SB. SB was a man who had been blind from birth due to cataracts. When he was 52, he had an operation which restored his sight and hence he could see. Thus, this case has shown the importance of eye-retina for things to be perceived. And therefore, supports both of theories of perception which eye-retina is essential for perception.

As vital organ of vision, the eye, allows us to learn more about the world around us more than any other organ or senses. Sight, the physical sensory experience and vision, the metaphysical concept of how our brain interprets images both work harmoniously and play a huge role in our everyday lives. However, almost a billion people are either blind or visually impaired simply due to not having a pair of glasses. Being able to lead people in the direction of good vision is what developed my interests.

After being shown a picture of an elephant they eye will take the light that is reflected from the object and it will enter the eye through the pupil. Then the light will be focused by the cornea and the lens to form a sharp image of the elephant in the retina. The retina is the network of neurons that cover the back of the eye and contains the visual receptors for a person vision. The visual receptors are made up of cones and rods that contain light sensitive chemicals called visual pigments. Visual pigments reacht to light and cause a triggered electrical signals to occur. These electrical signals will then flow through a network of neurons and this network of neurons is what makes up a persons retina. After the flow through the network of neurons occurs the electrical signals will emerge from the back of the eye in the area

The eye is the organ of sight. It is used in almost everything we do, from playing sport to reading. A normal and well functioning eye can focus objects and images, both near and far, perceive depth and adapt to changes in light.

My inspiration for wanting to become an optometrist was jump-started by my aunt Rosemary. My aunt suffers from dry macular degeneration, and she first started losing her eyesight when I was about five years old. I have always been close to her, and I have seen her vision deteriorate. Today she can see peripherally. I have watched as she lost her driving privileges and was forced into an early retirement. I always viewed my aunt's condition without an appreciation of how lucky I truly was to have normal vision. However, In the summer of 2002 I visited an optometrist for the first time. Since that first visit to the optometrist 13 years ago, my eyesight has drastically deteriorated. I currently have a correction factor of -7.25 in my right eye, and a correction factor of -8.0 in my left eye. My vision has stabilized, but my high correction power, coupled with observing my aunt's macular degeneration, allowed me to understand that the gift of vision may not be an everlasting gift. I want to do my best to help people make the best of what may not be an enduring attribute of their lives.

Tapeta can be classified according to their location in vertebrates and mechanism in invertebrates. Choroidal tapeta are the most common and are classified as tapetum fibrosum and tapetum cellulosum. The simplest type is the tapetum fibrosum, which is found principally in mammals, including herbivores (elephants, horses and goats), cetaceans (whales and dolphins), certain marsupials (Tasmanian Devil), and a rodent (Cuniculus pacas). The tapetum fibrosum consists of extracellular collagen fibrils that are stacked orderly with the majority of the its fibers running horizontally. The number of layered fibrils varies between species and can be up to several hundred thick. The most studied tapetum fibrosum among mammals is found in the cow and is located posteriorly and dorsally. The thickness is variable, increasing its thickness posteriorly. In species with a choroidal tapetum, the retinal epithelium in the area is the tapetum in un-pigmented, it allowing the light to pass subsequently reflected by the tapetum. This contrasts with the pigmented retinal epithelium

The eyeball holds many parts to allow eyesight. The retina holds the key to allowing the human eye to see color. The pupil appears as the black part of the eye that people see, the pupil however does not have much to do with comprehending color. As Clarence Rainwater said in his book “The pupil is simply the hole in the iris through which light enters the eye.” (84) The light then has to pass through many parts of the eye before reaching the retina such as the transparent cornea, the aqueous humor, the lens, and the vitreous humor. Clarence Rainwater described the retina as “... the eye’s sensitive inner surface.” (86) The exciting part of the eye starts here. The retina holds the key as stated by Clarence Rainwater, “... a complex system

The development of the human body is an exquisite process that involves numerous complicated processes for even the smallest of body parts, including the eyes. The eyes are an extraordinarily complex organ capable of gathering information through refracted light and sending it the brain to assemble a picture. They provide the ability to see and follow a moving object and the capability to tell an approximate distance of an object. When light passes through the cornea and iris pupil, at the anterior portion of the eye, it is focused by the lens onto the retina at the back of the eye. Photoreceptor cells, which are present in the retina, detect the light and send information to interneurons which begin to sort out the information. This information is then sent to ganglion cells which transmits the final information to the brain (Sowden 199). Because the eyes have such complicated and exquisite processes, the likelihood of developmental errors occurring are possible. A large number of these developmental errors lead to congenital defects and abnormalities that effect the individual’s eye sight. Some of these defects and abnormalities can cause serious diseases and syndromes that effect more than just the eyes, but also neurological processes, facial dimorphisms, growth failure, tracheal development, and genitalia anomalies.

Phase 2: Retina is placed in the back side of the eye and it has to „collaborate“ with cornea and lens in order to provide an image for

The combination of the lens and the tear film on the eye provides the total power of the contact lens or liquid lens power. A portion of the lens, surrounded by the peripheral fitting curves acts as the optical zone of the contact lenses.

The most effected part of the eye is the optic nerve. The optic nerve's main purpose is to connect the retina and the brain, as to send what the human is seeing to the brain to process the visual information. The optic nerve contains more than one billion nerve fibers which each give off their own electrical impulses to send the visual information to the occipital lobes in the brain. The occipital lobe then processes the information which it receives.

In the center of the iris is the pupil. Iris function is to control the size of the pupil. This pupil dilation allows a certain amount of light to enter the eye. A bright environment stimulates limiting diaphragm to contract the sphincter muscle and reducing the amount of light entering the eye. A dark room stimulates the dilator to relax and dilate in the effort to increase the amount of light entering the eye. The pupil constriction also occurs when the lens changes focus so that the eye can see something on a fence. This is known as the, Äúnear reflection., AU Sometimes the student does not respond properly due to problems in nerve or cranial

Fluid circulating inside the front portion of the eye is produced by a structure called the ciliary body, which is located behind the iris. This fluid moves through the opening of the pupil, passes into the space between the iris and the cornea, and drains out of the eye through a tissue called the angle. With glaucoma, the passing of fluid

Our eyes are vital organs because they help us visualize our surroundings. But are our eyes perfect in seeing what’s right in front of us? Sadly I learned in our evolution, nature messed up at one point and gave us blind spots in our eyes. This project shows why we have these blind spots, how to discover them, and how big they are. I researched on how our eyes see things; why when one eye is closed, the other eye sometimes can’t see what’s in front of it. I also found during my research a formula that is used to estimate the size of a human eye’s blind spot. I performed an experiment using Blind Spot Test card I made to verify the existence of blind spots in my eyes. I also collected data

The eye is an opaque eyeball filled with liquid. In the front of the eyeball is a transparent opening known as the cornea. The cornea is a thin membrane