Skip to main content

NCERT solutions for class 10 science The Human Eye and the Colorful World

NCERT solutions for class 10 science The Human Eye and the Colorful World

Today we will learn ‘The defects of vision and their correction’.

Defects of vision and their correction
The ability to see is called vision.It is also called an eyesight.Vision is known as ‘Drishti’ in Hindi. There are three common defects of vision or defects of the eyes:
  1. Myopia
  2. Hypermetropia
  3. Presbyopia
Myopia (Short-sightedness or nearsightedness)
Myopia is the defect of vision due to which a person cannot see the distant objects clearly, though he/she can see the nearby objects clearly. The far point of an eye suffering from myopia is less than infinity.
 The defect of the eye called myopia is caused:-
  1. Due to thehigh converging power of eye lens because of its short focal length.
  2. Due to the eyeball being too long.
In some cases, in an eye suffering from myopia, the ciliary muscle attached to the eye lens does not relax sufficiently to make the eye-lens thinner to reduce its converging power. So due to the greater converging power of the eye-lens in amyopic eye, the image of a distant object is formed in front of the retina and hence the eye cannot see it clearly.
Myopia is corrected using spectacles containing concave lenses. The concave lens used for correcting myopia should be of such a focal length that it produces a virtual image of the distant object at the far point of the myopic eye. The whole purpose of using a concave lens here is to reduce the converging power of the eye-lens.

Looking for CBSE Class 10 sample papers, NCERT solutions for class 10 science visit www.takshilalearning.com. It will enable you to review the complete subject matter for Class 10 designed by the experts.

Call us : 8800999280/8800999284

Labels:

Comments

Post a Comment

Thank you we will contact ASAP.

Popular posts from this blog

Last Minute Tips to Crack SSC CGL 2019-20 (Tier-I) Exam

Last-Minute Tips to Crack SSC CGL 2019-20 (Tier-I) Exam 1. Don’t read any new topic at the last moment · Try to avoid studying any new topic at the last moment. Just revise what you have already studied. 2. Don’t forget your Admit Card, Photograph and ID Proof · Take a print out of your admit card and original photo identity proof, 1 photo and photocopy of the ID proof. Reach the examination center before time to avoid any last-minute trouble. 3. Maintain your Speed & Accuracy and Maximize your Score · Speed and Accuracy are two important factors to crack any competitive exam. Speed will help in maximizing the attempts while accuracy will ensure that you don’t end up losing marks as the negative marking of 0.5 marks for wrong answers is there. 4. Attempt according to the strategy you followed in the mock tests · Make sure you attempt the easier section first. The exam should be attempted with the same strategy you fol...
4 comments
Read more

Online cbse coaching class for 11 Mathematics

Online cbse Class 11 maths : Online coaching classes for 11 maths  and for other subjects. We are here to solve students problem instantly, So that they can improve himself/herself. One to One Correspondence and Equivalent Sets Suppose the members of the family are dinning and plates are prepared on the table then there is a One to one correspondence between the set of family members and the plates prepared. We will indicate this correspondence by the symbol If each element of a set A is associated with one and only one element of a set B and each element of B is associated with one and only one element of set A, then the sets A and B are said to be in one to one correspondence. If both the sets are finite and if they are in one to one correspondence, it is obvious that they have the same number of elements. If two sets have the same number of elements, they are said to be equivalent sets. Using symbol, we write A B. Between two equivalent sets, a one to one corr...
Post a Comment
Read more

Magnetic and non-magnetic material Class 6 Science

Magnetic and non-magnetic material  Class 6 Science A magnet is a substance that is drawn to certain magnetic materials like iron, cobalt, and nickel. Magnets have the ability to draw iron to them. Natural magnets are rocks that naturally draw iron. Non-magnetic materials include things like wood, rubber, coins, feathers, leather, etc. that are not drawn to iron. Magnet characteristics It pulls magnetic materials, such as iron. The magnet's two ends are referred to as its poles. The magnet's diametrically opposed poles are drawn together. Heating, hammering, or dropping causes it to lose its characteristics. On the basis of properties types of Magnets Temporary magnets are those magnets that are magnetic for only a little duration. Typically, iron, cobalt, or nickel are used to make them. When they are close to the powerful magnet, they act like a magnet. When they are yanked away from the powerful magnet, they stop being magnetic. Permanent magnets are magnets that have magne...
Post a Comment
Read more