Advertisements
Advertisements
प्रश्न
A student is unable to see clearly the words written on the black board placed at a distance of approximately 3 m from him. Name the defect of vision the boy is suffering from. State the possible causes of this defect and explain the method of correcting it.
Advertisements
उत्तर
The boy is suffering from nearsightedness i.e. Myopia. The possible causes for this defect are Elongation of the eyeball.
Excessive curvature of the eye lens
This defect can be corrected by placing a concave lens in front of the eye.
APPEARS IN
संबंधित प्रश्न
What is the other name for
myopia
A man can read the number of a distant bus clearly but he finds difficulty in reading a book.
- From which defect of the eye is he suffering?
- What type of spectacle lens should he use to correct the defect?
A person suffering from the eye-defect myopia (short-sightedness) can see clearly only up to a distance of 2 metres. What is the nature and power of lens required to rectify this defect?
A person having short-sight cannot see objects clearly beyond a distance of 1.5 m. What would be the nature and power of the corrective lens to restore proper vision?
Differentiate between members of the following pair with reference to what is asked in bracket.
Myopia and hyperopia (cause of the defect)
State one role of ciliary muscles in the human eye.
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
Anuja cannot see the blackboard writing but she can see nearby things.
(a) What is the eye defect she is suffering from?
(b) State the possible reason for her defect.
(c) How is it corrected
A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power:
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?
