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Internal Structure of the Eye Biology EducatorSharmin
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#EducatorSharmin • #Biology • #EyeStructure • Internal Structure of Eye: • A vertical section of the eyeball shows that its walls are made up of three layers. The outermost layer is a tough, white, fibrous coat called the sclerotic coat, or sclera. When seen from the front it is recognizable as the white of the eye. The sclera forms a protective layer around the eyeball and continues as the transparent cornea which forms a small bulge at the front of the eye. Since the cornea is transparent, it allows light to enter the eye. It is a denser medium than air so light rays passing through it are refracted inwards toward the pupil and the lens. The cornea causes the greatest refraction of light. • The next layer is the choroid coat. This contains a network of blood capillaries that nourish the eye. The choroid coat is pigmented black, just as the inside of the camera is painted black. This prevents the internal reflection of light. • The anterior end of the choroid is modified to form the ciliary body and the iris. The ciliary body contains the ciliary muscle which alters the thickness of the lens. The iris is a circular, disc-shaped structure with a round eye, the pupil, in the centre. The pupil allows light to pass into the eye. The colour of the iris may vary, usually between blue to grey or green to brown. the size of the pupil changes to allow a suitable amount of light to pass into the eye, thus protecting the inner layer of the • eye from damage. In the dim light, more light must enter the eye in order to enable us to see clearly. • #EducatorSharmin • Get More Information:---------------------------------------- • 👉Website: https://educatorsharmin.blogspot.com • 👉Instagram: / sharminfiro. . • 👉Facebook: / sharminjahan499 • 👉Twitter: / educatorsharmin • 👉Linkedin: / sharmin-j. . • 👉Pinterest: / shanikaluja. .
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