Advertisements
Advertisements
प्रश्न
What is the far point and near point of the human eye with normal vision?
Advertisements
उत्तर
The near point of the eye is the minimum distance of the object from the eye, which can be seen distinctly without strain. For a normal human eye, this distance is 25 cm.
The far point of the eye is the maximum distance to which the eye can see the objects clearly. The far point of the normal human eye is infinity.
APPEARS IN
संबंधित प्रश्न
List three common refractive defects of vision. Suggest the way of correcting these defects.
What is the scientific name of
short-sightedness
What is the far point of a person suffering from myopia (or short-sightedness)?
An eye has a near point distance of 0.75 m. What sort of lens in spectacles would be needed to reduce the near point distance to 0.25 m? Also calculate the power of lens required. Is this eye long-sighted or short-sighted?
The defect of vision which cannot be corrected by using spectacles is:
(a) myopia
(b) presbyopia
(c) cataract
(d) hypermetropia
A person cannot see the distant objects clearly (though he can see the nearby objects clearly). He is suffering from the defect of vision called:
(a) cataract
(b) hypermetropia
(c) myopia
(d) presbyopia
The defect of vision in which the eye-lens of a person gets progressively cloudy resulting in blurred vision is called:
(a) myopia
(b) presbyopia
(c) colourblindness
(d) cataract
Describe the mechanism of focusing the image of a distant object in your eye when you raise your head after reading a book.
Explain the terms ‘adaptation’ and ‘accommodation’ with reference to the eye.
A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?
State the main functions of the following:
Tears
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
In what two whys is a yellow spot different from the blind spot?
Give Reason:
Why do we see clearly in the central region of the retina?
Give Technical Term:
The type of lens used to correct myopia is
Differentiate the eye defects: Myopia and Hypermetropia
Myopia and hypermetropia can be corrected by:
Observe the following diagram and answer questions following it:
- Identify the defect of vision shown.
- List its two causes.
- Name the type of lens used for the correction of this defect.
