Class 10 Science - Chapter The Human Eye and the Colourful World NCERT Solutions | When do we consider a person to be myopi
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?
Myopia is also known as nearsightedness. A person who is suffering from this eye defect cannot see the distant objects clearly. The normal vision of the eye is 25 cm. In this eye ball is longer than usual and light rays converge in front of the retina which forms the blurred image. The image is formed in front of the retina to the person who is having this defect. So, the person is advised or recommended to use a concave lens of the correct power. So, the image will form on the retina. Thus, this eye defect can be rectified.
Diagram of correction of myopia:
Hypermetropia is the eye defect also called nearsightedness. In this eyeball is shorter than the normal. When the light rays strike on the retina before convergence it forms a blurred image. A person who is having this defect can see the distant objects clearly but cannot see the near objects very clearly. This is because light rays from the object focussed at the point behind the retina. This condition can be corrected by using an appropriate convex lens.
Diagram of correction of Hypermetropia:
More Questions From Class 10 Science - Chapter The Human Eye and the Colourful World
- Q:-
Why do stars twinkle?
- Q:-
What is the far point and near point of the human eye with normal vision?
- Q:-
Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? Assume that the near point of the normal eye is 25 cm.
- Q:-
Explain why the planets do not twinkle.
- Q:-
What is meant by power of accommodation of the eye?
- Q:-
The human eye forms the image of an object at its
(a) cornea. (b) iris. (c) pupil. (d) retina.
- Q:-
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?
- Q:-
The least distance of distinct vision for a young adult with normal vision is about
(a) 25 m. (b) 2.5 cm. (c) 25 cm. (d) 2.5 m.
- Q:-
A person with a myopic eye cannot see objects beyond 1.2 m distinctly. What should be the type of the corrective lens used to restore proper vision?
- Q:-
Why does the sky appear dark instead of blue to an astronaut?
Popular Questions of Class 10 Science
- Q:-
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
- Q:-
What is a good source of energy?
- Q:-
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
- Q:-
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
- Q:-
What changes can you make in your habits to become more environment-friendly?
- Q:-
What is the difference between a reflex action and walking?
- Q:-
What is the importance of DNA copying in reproduction?
- Q:-
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
- Q:-
Why should a magnesium ribbon be cleared before burning in air?
- Q:-
Define the principal focus of a concave mirror.
Recently Viewed Questions of Class 10 Science
- Q:-
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
- Q:-
What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer.
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced. - Q:-
Which of the following pairs will give displacement reactions?
(a) NaCl solution and copper metal
(b) MgCl2 solution and aluminium metal
(c) FeSO4 solution and silver metal
(d) AgNO3 solution and copper metal. - Q:-
Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.
- Q:-
In evolutionary terms, can we say which among bacteria, spiders, fish and chimpanzees have a ‘better’ body design? Why or why not?
- Q:-
A concave lens of focal length 15 cm forms an image 10 cm from the lens. How far is the object placed from the lens? Draw the ray diagram.
- Q:-
A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil, (ii) withdrawn from inside the coil, (iii) held stationary inside the coil?
- Q:-
Draw the electron dot structures for
(a) ethanoic acid.
(b) H2S.
(c) propanone.
(d) F2. - Q:-
Why are some patients of diabetes treated by giving injections of insulin?
- Q:-
List the properties of magnetic field lines.
- All Chapters Of Class 10 Science
- All Subjects Of Class 10