Which of the following is true for the eye defect known as hypermetropia (farsightedness)?

Write the value of the near point of distinct vision for a normal eye.

Study the diagram and answer the questions that follow:
$(i)$ Identify the defect of vision represented by this diagram.
$(ii)$ List the two possible causes of this defect.
$(iii)$ With the help of a ray diagram,explain how this defect can be corrected.

At noon,the sun appears white because:

Sometimes you see a person reading the newspaper by placing it very close to his eyes. Which defect is he suffering from? How can the defect be removed?

$A$ person cannot see objects distinctly when placed at a distance less than $50\, cm$.
$(a)$ Identify the defect of vision.
$(b)$ Give two reasons for this defect.
$(c)$ Calculate the power and nature of the lens he should be using to see clearly the object placed at a distance of $25\, cm$ from his eyes.
$(d)$ Draw the ray diagrams for the defective and the corrected eye.