The far point of a myopic person is 120 cm in front of the eye. Find the focal length and the power of the lens required to enable to see distant objects clearly.

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

A short-sighted person cannot see objects beyond 50 cm from the eye. Determine the focal length and power of the lens that will enable him to see distant objects clearly.

A near point of hypermetropic person is 50 cm from the eye. What is the power of the lens required to enable the person to read clearly a book held at 25 cm from the eye?

A man used a concave lens of focal length 20cm.Find the power of the lens.

A person having a myopic eye uses a concave lens of focal length 20 cm. What is the power of the lens?

Find the focal length of a lens of power −2.0 D. What type of lens is this?

A person with a myopic eye is not able to see objects beyond 1.25 m from it. What is the nature, the focal length and power of the lens used to correct the' defect?

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.

A far sighted person has his near point 50 cm. Find the power of lens he should use to see at 25 cm clearly.