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प्रश्न
When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?
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उत्तर
- Myopia : When a person can see nearby objects clearly but cannot see distant objects distinctly then the person is suffering from myopia. A person with this defect has the far point nearer than infinity. Myopia is also known as near-sightedness.
Myopia eye - Correction of Myopia : Wearing of concave lens diverges the light rays to help the image to be focused on the retina, hence myopia is corrected using the concave lens of suitable focal length.
Correction for Myopia - Hypermetropia: When a person can see distant objects clearly but cannot see nearby objects distinctly, then the person is suffering from hypermetropia. The near point, for the person, is farther away from the normal near point (25 cm). Hypermetropia is also known as far-sightedness.
Hypermetropic eye - Correction of hypermetropia : Wearing a convex lens in front of a hypermetropic eye converges the light rays to help the image to be focused on the retina, hence this defect is corrected using the convex lens of suitable focal length.
Correction of hypermetropia eye
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संबंधित प्रश्न
What is the far point and near point of the human eye with normal vision?
Which defect of vision can be rectified:
by using a concave lens?
What is the scientific name of
short-sightedness
What is the scientific name of
long-sightedness?
Where is the near point of a person suffering from hypermetropia (or long-sightedness)?
Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class.
What type of lenses-converging or diverging-would an optician prescribe for her?
Explain with the help of labelled ray diagram, the defect of vision called myopia and how it is corrected by a lens.
A person is unable to see distinctly the objects closer than 1 m. Name the defect of vision he is suffering from. Draw ray diagrams to illustrate the cause of the defect and its correction by suitable lens.
State one role of ciliary muscles in the human eye.
Draw a ray diagram to show how Hypermetropia is defect can be corrected using a lens.
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
Select the odd one in the following series:
Endolymph, Tympanic membrane, Semi-circular canal, Blind spot.
Write whether the following is true or false:
A convex lens is used for correcting myopia.
Give Technical Term:
The path which responsible for protecting the eye from sweat.
Give Technical Term:
The type of lens used to correct myopia is
Given below is a diagrammatic representation of a defect of the human eye:
(i) Identify the defect.
(ii) Mention two reasons for the above defect.
(iii) State how the defect can be rectified.
(iv) Name the part of the eye responsible for maintaining the shape of the eyeball.
Choose the Odd One Out:
Write scientific reason.
Nearsightedness, this defect can be corrected by using spectacles with concave lens.
Myopia may arise due to ____________.
A teacher drew the diagram of the heart on the blackboard and told the students to copy it in their notebooks. Mahesh couldn't see the diagram clearly as it appeared blurred to him.
- Name the defect of the eye Mahesh is suffering from.
- Where is the image formed in this defect?
- Mahesh consults an eye doctor and is prescribed suitable lenses to correct the defect. Which type of lens do his spectacles have?
