A 77 year old man has a near point of 115 cm. What power lens (in diopters) does the man need in order to be able to see an object clearly at the normal near point of 25 cm? Assume that the man will get contact lenses, that is neglect the two centimeters that glasses would be away from the eye. ok so the goal here is to move the objects image from 115 cm to 25 cm. i am going to use the equation 1/s+1/s'=1/f and 1/f=P so this looks really simple, but i am not getting the right answer. for 1/f or P i am getting 4.87 d. and i converted to meters before i did the calculation. please help me.