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Our topic for today is Human Eye.
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The human eye is one of the most valuable sense organs that enables us to see the world around us.
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Let us study about the different parts of an eye.
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Sclera is a tough outer coat that protects the entire eyeball.
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Choroid is a vascular layer of the eye.
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It contains blood vessels that nourish the inner parts of the eye.
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Hurry.
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Please sit properly.
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Sorry.
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No Worries.
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Cornea is the front portion of the eye.
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It is convex in shape and bulges outside.
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Light enters the eye through the cornea.
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Hey.
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Iris is a dark muscular diaphragm located just behind the cornea.
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It regulates the amount of light entering the eye by adjusting the size of the pupil.
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Pupil is a hole in the middle of the iris.
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Size of the pupil decreases or increases depending upon the intensity of light entering the eye.
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Eye lens is made up of a transparent jelly like substance, which is made up of proteins.
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It is held in position by the ciliary muscles and suspensory ligaments.
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The ciliary muscles and suspensory ligaments adjust the focal length of the eye so that we can see distant and nearby objects clearly.
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The ability of the eye to focus on distant and nearby objects by changing the focal length is called accommodation.
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Please go inside.
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Aqueous humor is a viscous liquid filled in the area between the cornea and eye lens.
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It prevents the eye from collapsing due to changes in the atmospheric pressure.
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Where are you going?
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I was just taking a walk.
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Please get inside. I don't want to be late.
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Hey
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Hey
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Retina is a delicate membrane having a large number of light sensitive cells.
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The light sensitive cells get activated upon illumination and generate electrical signals.
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The light sensitive cells are are of two types.
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Rods: Cells that respond to the intensity of light.
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Cones: Cells that respond to the color of objects.
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Hey.
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What is this?
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This is the macula.
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It is a tiny area in the retina which is responsible for clear and sharp vision.
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Hey.
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Did you know that there is a small depression inside the macula.
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It is called the fovea centralis.
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Here, maximum number of cones are present.
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An inverted real image of the object is formed on the retina.
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The electrical signals generated by the cells are sent to the brain through the optic nerve.
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The brain reassembles the signals into a meaningful image and gives rise to the sensation of vision.
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Come on.
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Bravo.
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Seems like jelly.
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Vitreous humor is a jelly like substance filled in the space between the retina and the eye lens.
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It helps in maintaining the shape of the eye.
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Blind spot is a small region in the retina where the optic nerve enters the eye.
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It is insensitive to light.
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Hence, it is called the blind spot.
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Different parts of an eye.
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Sclera, Choroid, Cornea, Iris, Pupil, Eye lens, Ciliary muscles, Suspensory ligaments, Aqueous humor, Retina, Vitreous humor, Optic nerve, Blind spot
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We forgot something.
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Macula.
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Fovea centralis.
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Thank you.