An eye has a far point of 2 m. What type of lens in spectacles would be needed to increase the far point to infinity? Also calculate the power of lens required. Is this eye long-sighted or short-sighted?

This is a case of short sightedness. Concave lens of focal length 2m should be used to curb this defect. The power of this lens should be:

Power = 1/focal length

Power = 1/(-2)

Power = -0.5 D.