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DetailsVision is considered one of the most important senses in humans, and over 60% of the brain is involved in the processing of visual input. Visual input of many different frequencies and intensities are all analyzed and processed by the brain. Each eye has a visual field that spans approximately 150°, and the visual field of both eyes overlap. This enables our brain to compensate for the blind spot and increases the binocular visual field. Having binocular vision also enables depth perception.
Vision Fact SheetCheck out the fact sheet on vision on the left, provided by the Dana Foundation.
PhotoreceptorsThere are two types of photoreceptors in the retina, which detect light and are responsible for vision. 95% of photoreceptors are rods, which function in low light. Rods are also distributed on the outer edges of the retina, and are used in peripheral vision. The other type of photoreceptor, cones, are able to detect color, but need more light to function.
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The Eye |
Vision Pathway |
The eye is a light-detecting organ that sends signals based on visual stimulus to the brain through the optic nerve. It enables us to differentiate colors and depth, and it contains a sheet of photoreceptors in the retina. Below is a diagram of the eye.
Additional ResourcesCheck out these links for more information about vision!
Neuroscience Online: nba.uth.tmc.edu/neuroscience/m/s2/chapter14.html Medicine Net: medicinenet.com/image-collection/eye_anatomy_detail_picture/picture.htm KenHub: kenhub.com/en/library/anatomy/the-visual-pathway |
Signals detected by cells in the retina pass through the following pathway to the brain where they are processed and analyzed. After light is picked up by photoreceptors in the retina, the signal is transmitted through the optic nerve, crossed over at the optic chiasm, and relayed to the lateral geniculate nucleus in the thalamus. Eventually, the signal is sent to the primary visual cortex in the occipital lobe to be integrated.
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