Advertisements
Advertisements
प्रश्न
Explain the Term: Cataract
Advertisements
उत्तर
Cataract: It is a condition in which the lens turns opaque and the vision is cut down even to total blindness. It can be corrected by surgically removing the lens and by using spectacles with highly convex lense.
संबंधित प्रश्न
What is myopia?
the biological/technical terms for the lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.
What is the scientific name of
long-sightedness?
Name any two defects of vision which can be corrected by using spectacles.
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?
Given alongside is a diagram depicting a defect of the human eye. Study the same and then answer the questions that follow:

- Identify the defect.
- Name the parts labelled 1, 2 and 3.
- Give two possible reasons for this eye defect.
- Draw a labelled diagram to show how the above mentioned defect is rectified.
Given below is a diagram depicting a defect of the human eye? Study the same and answer the question that follow:

Draw a labeled diagram to show how the above mentioned defect is rectified using the lens named above.
Assertion: Concave mirrors are used as reflectors in torches, vehicle head lights and in search lights.
Reason: When an object is placed beyond the center of curvature of a concave mirror, the image formed is real and inverted.
Draw ray diagram showing myopic eye.
