Construction of an Eye
Construction of an Eye
Construction Of Eye: The eye performs three functions: it makes adjustments to admit appropriate amount of light, it bends the rays of light to form a sharp image, and it collects and sends information about the image to the brain for further 'processing. Eye allow to learn more about the surrounding world that we do with any of the other four senses. Different parts of the eye perform these functions. The figure shows schematically the basic components of the human eye.
The different parts of the eye are contained within the spherical eyeball, which is about 2.5 cm in diameter. An opaque, white, protective membrane called the sclera covers most of the outer part of the eyeball and is known as white of the eye. A small portion at the front of the eyeball bulges out. A transparent protective membrane called the cornea covers this portion.
The choroid, is the vascular layer of the eye, containing connective tissues, and lying between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm.
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Behind the cornea the major structures of the eye consists of
Iris: It controls the amount of light entering the eye by changing the size of the pupil.Pupil is the hole int he middle of the iris through which light enters the eye.
Crystalline Lens: It helps in bending light.It is a convex lens made up of transparent and jelly like material. The size of its curvature can be adjusted witrh help of ciliary muscles.These are the muscles which are attached to the eye lens and leads to the variation in the focal length of the lens. The lens divides the eye into two chambers. The smaller of these two is between the cornea and the lens. It is filled with a watery fluid called the aqueous humour. The larger chamber, between the lens and the retina, is filled with jellylike fluid called the vitreous humour. This fluid helps in maintaining the shape of the eyeball.
Retina: It is a light sensitive screen inside the eye on which the image is formed. It contains rod and cone cells for recognisisng different colours.
Optical nerves:These nerves which take the image to the brain in the form of electrical signals.
A small area on the retina of the where no visual image can be formed is called the____________. | |||
| Right Option : A | |||
| View Explanation | |||
The middle vascular coat that darkens the eye chamber and prevents refraction by absorbing the light rays is _______________. | |||
| Right Option : A | |||
| View Explanation | |||
Refractive power of cornea in human beings is appoximately _______________. | |||
| Right Option : C | |||
| View Explanation | |||
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My experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
Shivam Rana
7thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Shreya Shrivastava
8thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
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Barkha Arora
10thAbhyas institute is one of the best coaching institute in the vicinity of Ambala Cantt area. The teachers of the institute are well experienced and very helpful in solving the problems of the students.The good thing of the institute is that it is providing extra classes for the students who are w...
Aman Kumar Shrivastava
10thWe started with lot of hope that Abhyas will help in better understnding of complex topics of highers classes. we are not disappointed with the progress our child has made after attending Abhyas. Though need to mention that we expected a lot more. On a scale of 1-10, we would give may be 7.
Manya
8thUsually we see institutes offering objective based learning which usually causes a lag behind in subjective examinations which is the pattern followed by schools. I think it is really a work of planning to make us students grab the advantages of modes of examination, Objective Subjective and Onli...
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Barkha Arora
10thAbhyas institute is one of the best coaching institute in the vicinity of Ambala cantt.The institute provides good and quality education to the students.The teachers are well experienced and are very helpful in solving the problems. The major advantages of the institute is extra classes for weak...
Shreya Shrivastava
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Yogansh Nyasi
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Cheshta
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Hiya Gupta
8thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
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Aman Kumar Shrivastava
10thThird consective year,my ward is in Abhyas with nice experience of admin and transport support.Educational standard of the institute recumbent at satisfactory level. One thing would live to bring in notice that last year study books was distributed after half of the session was over,though study ...
Ayan Ghosh
8thMy experience with Abhyas academy is very nice or it can be said wonderful. I have been studying here from seven class. I have been completing my journey of three years. I am tinking that I should join Abhyas Academy in tenth class as I am seeing much improvement in Maths and English
Hridey Preet
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Om Umang
10thIn terms of methodology I want to say that institute provides expert guidence and results oriented monitering supplements by requsite study material along with regular tests which help the students to improve their education skills.The techniques of providing education helps the students to asses...
