A person wears glasses of power − 25 D. Is the person farsighted or nearsighted? What is the far point of the person without the glasses?
Given that the power m, is -25D which means person must be near-sighted
For a near-sighted person, the point where object is placed u = ∞
Focal length, f can be calculated from the power as-
Using lens formula –
Substituting the values-
Hence, the far point for the near-sighted person is 40 cm.