The Dawn Of Retinal Prosthetic Devices

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

Focusing an image clearly onto the retina is the initial step in the process of vision, but although a sharp image on the retina is essential for clear vision, a person does not see the picture on the retina. Vision occurs not in the retina, but in the brain. Before the brain can create vision, the light on the retina must activate the visual receptors in the retina by a two-element

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

Flynn was able to detect the pattern of horizontal, vertical and diagonal lines on a computer screen using the implant”. You will go from seeing only the light perception to being able to see your hand movement and count your fingers but “the implant cannot provide any highly detailed vision - but previous studies have shown it can help patients to detect distinct patterns such as door frames and shapes”. The patient will be able to change his/hers field of vision by each electrode to be able to customize the best way to make out shapes or contrasts to suit their lives and different activities. Yes, the vision will be black and white, mainly in grayscale “Patients with retinitis pigmentosa see at most when the light is on or off. With the bionic eye they will not fully recover the vision: they will see in black and white - by contrasts -, and will greatly improve their ambulatory capacity”. Though this type of vision will not be good enough to compare with say someone with normal vision and is by no standards enough to let someone live like a normal person, but the fact that something like this is possible is no doubt an important and very hopeful advance in

The research topic I will be introducing is Age-Related Macular Degeneration. This has been classified as a degenerative disorder that distresses the macula in one’s eye. AMD is unfortunately a common illness that individuals over 65 suffer from and that is a central cause vision loss. AMD doesn’t have a set disease pathway, in some individuals it advances slowly so that loss of vision does not arise for a long time. The disease can also advance much quicker and may lead to lack of vision in either or both eyes. The disease begins a blurry area near the center of one’s vision which grows larger and larger possibly causing a blank space in the eye (Boyd, 2013). Research is being done on AMD because it is a prevalent illness and has extreme consequences.

Retinitis pigmentosa is a group of inheritable diseases that is characterized by gradual deterioration of the photoreceptors in the retina. The photoreceptor cells in the retina, rod cells, are light sensitive cells that are able to sense low levels of light. The frequency of retinitis pigmentosa is one in four thousand births (Deng et al., 2015; Fahim et al., 2012; Haddad et al., 2016; Shu et al., 2012) People affected by retinitis pigmentosa will typically exhibit symptoms of night-blindness first, and this will precede a loss in the patient’s visual acuity field that starts from the outer edge and gradually moves inward resulting in a much smaller visual field and loss of peripheral vision, also known as tunnel vision (Haddad et al., 2016).

The study proposed herein aims to accomplish the following: To determine the optimal exposure, gamma, contrast, and brightness corrections necessary to increase the perceived contrast of images by individuals affected by Retinitis Pigmentosa (RP) and to determine the optimal image overlay of input signals corrected at both high and low thresholds such that perceived contrast is maximized. Additionally, this study will develop an I/O system of minimal necessary size responsible for image processing following image acquisition from micro cameras that will output post-processed image data onto small, high resolution LCD/LED screens contained in a wearable binocular device similar to commercially available home theater glasses. Lastly, this

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 eye is made up of many components, including the cornea, pupil, iris, and retina, along with others. Within the retina are rods, cones, and a fovea. Rods are responsible for the black, white, and gray colors we see, along with our peripheral vision. Our cones help us see detail, along with allowing us to see colors, specifically red, green, and

The first disease I’m going to mention is Glaucoma, according to Web MD last updated in 2015, Glaucoma is a condition that causes damage to your eye's optic nerve and gets worse over time. It's often associated with a buildup of pressure inside the eye. Glaucoma tends to be inherited and may not show up until later in life.

     Macular Degeneration is a problem in the part of the eye that controls your sharpest central vision. It is a group of diseases that result in a loss of detailed vision. The brain will not just leave the spot empty, so it learns to fill it in with spotty macular cell damage. People most of the time don't tell their doctors (opthalmologists) about it until it is well in advance.

Patients with retinitis-pigmentosa are implanted with electrode arrays, which, when stimulated, create the perception of vision. Initially, I test to screen candidates for eligibility based on their light perception ability. If deemed eligible, I carry out device calibration and visual-function testing post-implantation. Active communication within the team is imperative throughout this process. Initially, the research coordinator identifies candidates and establishes a project timeline.

Take a second, and imagine your life as a teenager, fresh out of college with, aspiring to get a degree in whatever your heart desires. You’ve got lots of ambition and potential. The world is at your fingertips; you can do anything you set your mind to. But one day, tragedy strikes and the unthinkable happens: you lose a limb. Why is not important, but what the future entails is. Let’s say this limb is your right arm, the one you have used all your life to write, eat, type and play the guitar. Now let’s change the scenario a little bit. Instead you’ve lost your legs in a horrific car accident where both were crushed under the weight of the dashboard as your car collided with the 4x4 in front of you. You wake up the next day in the hospital groggy, barely remembering what happened. Shock is the only thing running through your mind the moment you look down to see your legs missing. Your brain thinks they’re still there because yesterday you were just getting out of bed for your morning jog. All that remains are the stubs where your legs used to be and the unbearable thought of being confined to a motorized chair for the rest of your life.

This will cause the light ray to then be converged by the cornea and lens to produce an image on the retina like it should

The eyelids are made up of four layers, the skin, muscle, connective tissue and conjunctiva. The process of vision occurs when light waves from an object, enter through the iris. Light then passes through the lens of the eye, a double convex structure that is used to focus the light, and then reaches the retina. Inside the retina are rods and cones. Rods are used to sense light and dark, and cones are used for sensing colors. Whether the light entering the eye hits the cones or rods, a signal is sent across the optic nerve to the brain where it is processed and viewed as an image. Some issues people have with eyesight are as follows. Those who are farsighted are unable to see things clearly at a short distance, compared to a long distance. This occurs when the light that enters the eye is focused behind the retina, and not directly onto it. When the cornea is not curved enough, this happens. Nearsightedness is when one can see objects clear at a short distance, but not at a longer distance, and this is often caused by a change in the cornea. A Blind spot is the location the optic disk, where the optic nerve fiber exits, and at this location there are no cones or rods, so there is a blind spot.