Suppose your friend wears prescription glasses of power +2.5 D. Where is her near point?

Question

Quizplus · Accepted Answer

The power of the glasses is +2.5 D, which means the focal length is 1/2.5 meters or 0.4 meters (40 cm). The near point for a person with normal vision is typically 25 cm. Using the lens formula (1/f = 1/v - 1/u), where v is the image distance (near point for normal vision) and u is the object distance (near point for the person), we find that the near point is approximately 66.67 cm.

Suppose Your Friend Wears Prescription Glasses of Power +2