Retinal Implants

* Electro-oculogram- Measures the corneo-retinal standing potential that exists between the front and back of the human eye.

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

Also, on the retina is the optic disk. There are no photoreceptors in this area, so any light that falls on this part of the retina is unseen and creates what is called the blind spot. (Hugh

The final option for microelectrode replacement is at the suprachoroidal, or outer retina level. Suprachoroidal placement is beneficial in that it has a safe and simple surgical process, with limited clinical worries, and can stimulate areas other than just the retina, for injuries to the optic nerve or another visual necessity. However, suprachoroidal alignment is far from the target area of the retina, and therefore has the highest stimulus threshold and requires the most electrodes of all options(Shepherd et al.,

The primary focusing lens is the cornea, the clear window at the very front of your eye. The internal lens, called the crystalline lens, is adjustable and alters your focus from distance to near. Sometimes, one of these two lenses may have a radius of curvature that is too steep. In myopia, it is often the cornea that is too highly curved. It is this curvature which is altered in laser eye surgery. Shortening the eyeball has been tried, but it has not been without the potential of serious and permanent damage. Often in situations where the crystalline lens is forced into an excessive plus power curvature, myopia can result. This may occur from near vision stress, a

Retinitis Pigmentosa (RP) is one of such currently untreatable causes of blindness. RP, along with Age Related Macular Degeneration (AMD) are amongst the more frequent causes of blindness in the developed world (Greenwald 2009), while RP itself is the leading cause of inherited blindness (Palanker 2004).

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

As humans, we don't always see with our eyes, but often with our imagination (Grunwald, 2016). Often times as people we never realize how useful our vision really is to us. You really don't think about something like that until it would actual happen to you. Throughout this essay, you will learn how the body is affected by Macular Degeneration (MD). Different signs and symptoms, as well as the etiology of MD, will be discussed. In the following, diagnosis tests and treatments may also be listed in order to help others who would like to know more about MD. Not to mention, you will learn the incidence and progression of MD. Furthermore, information though agencies and associations, as well as new research about MD will be given.

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.

These cells are called cones and rods, the cones help us see color and the rods aid in night and side vision. When we see an image all these parts of the eye send a message to the brain through the optic nerve. The images are sent upside to our brain, and then our brain turns them the right side up and helps us understand what we are seeing. When an injury happens to any part of the eye, the pattern of receiving and sending messages is impaired, therefore some people are entirely blind or experience color

In the 1920's, it was discovered that by placing electrodes on the skin in the region of the eyes, one could record electrical activity which changed in synchrony with movements of the eye in the head. It was initially believed that these potentials reflected the action potentials in the muscles that are responsible for moving the eyes in the orbit.

Light must pass through the cornea, aqueous humor, lens and vitreous humor before reaching the retina. It must then pass through the inner layers of the retina to reach the photoreceptive layer of rods and cones.

The iris is a thin diaphragm made of connective tissue and smooth muscle fibers. It lies between the cornea and lens. The iris is composed of three layers including endothelium, stroma and epithelium. The anterior chamber, the space between the cornea and the lens is divided into two chambers. The patterns that form the structure of the iris are unique to each person. Like fingerprints, iris pattern complexity can potentially identify a person.

Bionic eyes were made to restore the vision of blind men and women. Bionic eyes aren’t really eyes yet. They are a pair of glasses connected to a tiny camera and its transmits high frequency radio signals to a microchip that implanted in the top of the eyes. Electrodes that are implanted in the microchip send signals to stimulated cells in the retina, which connect to the optic nerve. These signals are passed down the optic nerve to the brain, which illuminate a

The bionic eye is a robotic ‘visual prosthesis’ (Dr. John D. Bissell, August, 2015) that can restore a sense of sight. The bionic eye is an electrical device that uses electrical signals to provide a sense of sight to patients with a healthy optic nerve. Patients with ‘some forms of hereditary blindness such as retinitis pigmentosa’ (BIONIC VISION TECHNOLOGIES, 2015) benefit from this prosthesis as retinitis pigmentosa destroys the photoreceptors, not the retinal cells or optic nerve. As well as stimulating retinal cells, the bionic eye can stimulate the visual system in the