Photoreceptor Damage: Causes and Possibilities :: Medical Medicine Papers

Photoreceptor Damage Causes and Possibilities over 10,000,000 people around the world suffer from some sort of cecity or handicap due to photoreceptor damage. These effects can be caused by a number of afflictions, including retinitis pigmentosa, macular degeneration, and tumors. These illnesses vary in severity from being a mere hindrance to completely blinding the individual. Until recently, those affected were left without commit of a cure or even a treatment that would jolly improve their vision. But over the last few years, several groups of scientists render been working on a partial cure in the invent of neuroprostheses, artificial devices which be inserted in the eye behind or on top of the damaged retinal area. These photoreceptive chips, in theory, should provide information alike the healthy neurons residing in the retina, substituting for the damaged photoreceptors.When we open our eyes, millions of tiny events supervene that give up us to see. Our pupils automati cally constrict in accordance to the weakly level, the variable lens bends and adjusts to fit the distance of what we are looking, and our photoreceptors tempt information in accordance to the previous factors. (This is extremely simplified, but it willing suffice for now.) Photoreceptors are tiny, specialized neurons located in the retina at the stern of the eye. There are two types of photoreceptors, rods and strobiluss. Each follow the same principles when well-to-do hits them they respond with a chemical reaction using a aggregate known as rhodopsin. Once this reaction occurs a chain of events takes this nitty-gritty down a number of sophisticated and specialized neurons, eventually grasp the brain and resulting in what we call sight.Rods (numbering one hundred million or so in each eye) are primarily in the periphery of our visual field. They are extremely sensitive to light and are practically tied together on a lower level to allow for greater sensitivity. Rods do non see in with good proclamation and cannot differentiate colors.Cones (only five million or so exist) are loosely found on the center of the visual field, a place called the fovea. The language you are reading now are being processed by cones in the fovea. They operate in brighter light than rods and detect color (there are three types, each responding to a particular range of wavelengths). Cones do not pool their output and exist for resolution, not mere detection. The only drawback with the cone system is the amount of light saturation necessary to stimulate them and send their signal to the brain.