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प्रश्न
Given below is a diagram depicting a defect of the human eye. Answer the questions that follow:
- Give the scientific term for the defect.
- Mention one possible reason for the defect.
- What type of lens can be used to correct the defect?
उत्तर
- Myopia (short-sightedness)
- There are two possible reasons for myopia one is the eyeball is lengthened from front to back and the other is the lens is too curved. Both these reasons might as well occur together.
- Myopia can be corrected by using a suitable concave (diverging) lens which causes the light rays to diverge before they strike the lens of the eye.
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संबंधित प्रश्न
Write the function of the following part of the human eye: crystalline lens
How does the eye regulate the amount of light that falls on the retina?
The size of the pupil becomes ______ when you see in dim light.
What is the function of the lens in the human eye?
Which of the following controls the amount of light entering the eye?
(a) ciliary muscles
(b) lens
(c) iris
(d) cornea
The descriptions of five kinds of images are given below:
(a) diminished and virtual
(b) enlarged and real
(c) enlarged and erect
(d) real and inverted
(e) virtual and the same size
Which one of these describes the image formed:
(i) on the retina of the eye?
(ii) by a magnifying glass?
(iii) by a convex driving mirror on a car?
(iv) by a plane mirror?
(v) on the screen of a slide projector?
Suggest how your irises help to protect the retinas of your eyes from damage by bright light.
Which part brings the image into sharp focus on the retina? How does it do this?
With reference to the functioning of the eye, answer the question that follow:
What is the shape of the lens during distant vision?
The figure below compares a part of our eye with a part of a photographic camera.
Name the corresponding parts of the eye the camera shown here that are comparable in function.
State the function of each of the following parts of the human eye:
(i) Cornea
(ii) Iris
(iii) Pupil
(iv) Retina
Millions of people of the developing countries are suffering from corneal blindness. This disease can be cured by replacing the defective cornea with the cornea of a donated eye. Your school has organised a campaign in the school and its neighbourhood in order to create awareness about this fact and motivate people to donate their eyes after death. How can you along with your classmates contribute in this noble cause? State the objectives of organising such campaigns in schools.
State the main functions of the following:
Coronary Artery
Name the following:
The pigmented circular area seen in the eye.
Name the following:
The region in the eye where the rods and cones are located.
State the Function:
Visual purple
Name the capacity of the eye lens to change its focal length as per need.
Write an Explanation.
Minimum distance of distinct vision
Write an Explanation.
Farthest distance of distinct vision
Which one of the following statements is NOT correct?
With reference to human eye answer the question that follow:
Name the part of the eye associated with the regulation of the shape of lens.
