Farsighted or hypermetropic eye can be corrected by converging (positive) lens

A plano-convex lens is made of glass of refractive index 1.5. The focal length f of the lens & the radius of curvature R of its curved surface, are related by f=2R

Magnification produced by a lens m is given by v/u

An equi-convex thin lens (??=1.5) of focal length in air as 30cm is sealed into an opening in one end of tank filled with water ((?=1.33). At the end of the tank opposite the lens is a plane mirror, 80 cm distant from the lens. The position of the image formed by the lens-water-mirror system of a small object outside the tank on the lens axis and 90cm to the left of the lens will be 41.5 cm to the right of the lens