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Near Point

The near point is the nearest distance at which an object can be seen clearly without strain.

In one line: Near point means nearest clear point.

Practice This Concept

Understand it

For a normal adult eye, the near point is about 25 cm. If an object is brought closer than this, the eye cannot focus it sharply on the retina. The near point depends on the eye's power of accommodation and can change with age or vision defects.

Example

A textbook held at 25 cm is usually readable clearly, but if it is brought too close, the letters may blur.

Formula and rule

For a normal adult eye, the near point is approximately 25 cm.

See it worked out

Follow the example line by line, then use the same method on new questions.

Worked example

  1. 1If a child can read clearly only when the book is kept at 30 cm, then the near point for that eye is 30 cm, not 25 cm.
  2. 2This may suggest a vision defect or reduced accommodation.

Method you can reuse

  1. 1Find the nearest distance at which the eye sees clearly.
  2. 2State that this distance is the near point.
  3. 3For a normal adult eye, mention 25 cm.
  4. 4If a different value is given in a case, use that value for the specific eye.

Sketch it in your answer

Show a near object placed at 25 cm from the eye and another placed closer than that. Mark the clearer position as the near point.

Check yourself

Answer the question in your head before opening the answer.

Try it yourself

What does the near point of an eye tell us in a clear school-level answer?

Think first, then show answer
The near point tells us the nearest distance at which the eye can see an object clearly without strain. For a normal adult eye, this distance is about 25 cm.

Common wrong answer

A common wrong answer is to call the near point the farthest visible distance. That is incorrect; the farthest distance is called the far point.

Don't mix this up

Students often think the near point is the closest distance for any eye, but it is the closest clear distance for a particular eye, and it can vary.

Exam tip

Remember the standard near point of a normal adult eye as 25 cm unless the question states otherwise.

Write it in the exam

Each point is worth about one mark. Write point 1 for a 1-mark question and keep adding points as the marks go up.

How CBSE asks it

State the definition of near point, give the standard value for a normal eye, or identify the effect of a changed near point in a case-based question.
  1. 1

    Enough for 1 mark

    The near point is the nearest distance at which an object can be seen clearly without strain.

  2. 2

    Add for 2 marks

    Example: A textbook held at 25 cm is usually readable clearly, but if it is brought too close, the letters may blur.

  3. 3

    Add for 3 marks

    For a normal adult eye, the near point is about 25 cm.

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