Visionaries for Vision Joaquin Sabherwal (Year 6, Shackleton)
INTRODUCTION We would all like to be young and healthy forever. However, as people inevitably age, their hair will begin to decolour, their joints will become stiffer, and their skin will begin to wrinkle. The wear and tear of our bodies is unavoidable as we get older, but perhaps one of the worst aspects of the ageing process is the possibility of losing one’s sight.
HOW DOES THE EYE WORK? Light reflects off objects and into our eyes. These rays of light enter the eye via the cornea, the pupil and the lens, and then focus on the retina. The retina is a light-sensitive tissue at the back of the eye, which sends signals through the optic nerve to the brain. It is these signals that become the images that we see [1].
Figure 1: Light reflects off objects and into our eyes [1][2] The macula is the area of the retina that gives us our central vision, and the peripheral retina surrounds the macula and gives us our side vision. On the retina, there are about 130 million tiny cells called photoreceptors [2]. These rod- and cone-shaped cells are input cells; they turn light into electrical currents that travel from the output cells, through the optic nerve and to the brain. When light enters the eye, it strikes these cells, which triggers a chemical reaction that sends signals to the brain [3].
Figure 2: The Retina and Photoreceptors [3]
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