Photoreceptor Damage: Causes and Possibilities :: Medical Medicine Papers

Photoreceptor Damage Causes and PossibilitiesOver 10,000,000 people around the homo suffer from some sort of blindness or handicap out-of-pocket to photoreceptor damage. These effects can be caused by a count of afflictions, including retinitis pigmentosa, macular degeneration, and tumors. These illnesses alter in severity from being a mere hindrance to totally blinding the individual. Until recently, those affected were left without hope of a cure or even a treatment that would somewhat improve their vision. But everyplace the last few years, several groups of scientists have been working on a partial cure in the form of neuroprostheses, artificial devices which are inserted in the eye behind or on top of the damaged retinal area. These photoreceptive chips, in theory, should provide information too the healthy neurons residing in the retina, alter for the damaged photoreceptors.When we open our eyes, one thousand millions of tiny events occur that allow us to see. Our pupil s mechani recollecty constrict in consent to the commence level, the variable lens flex and adjusts to fit the distance of what we are looking, and our photoreceptors receive information in accordance to the previous factors. (This is super simplified, but it will suffice for outright.) Photoreceptors are tiny, vary neurons located in the retina at the back of the eye. There are devil types of photoreceptors, rods and cones. Each follow the same principles when light hits them they respond with a chemic reaction using a substance known as rhodopsin. at once this reaction occurs a chain of events sends this message down a number of sophisticated and specialized neurons, eventually reaching 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 often tied together on a lower level to allow for greater sensitivity. Rods do not see in w ith good resolution and cannot differentiate colors.Cones (only five million or so be) are mostly found on the cracker of the visual field, a place called the fovea. The words 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.