<prompt> Prescription of presbyopic lens to a 50 year old emmetropic individual?0.50 D1.00 D1.50 D1.75 D  <response>: A rough estimate of the power of presbyopic glasses in an emmetrope can be made from the age as follows:- 40 years: 1.00 DS 45 years: 1.25 DS 50 years: 1.75 DS 55 years: 2.00 DS 60 years: 2.25 DS 65 years and above: 2.50 DS 