The discussion focuses on calculating the focal length of a spectacle lens required to correct hyperopia for a person with a near point of 1.10 m. The correct formula used is 1/f = 1/p + 1/q, where p is the distance of the object (0.25 m) and q is the distance of the image. The correct focal length, after considering that the image must be on the opposite side of the lens, is determined to be 0.324 m. Participants emphasize the importance of correctly identifying the sign of q in the lens formula to arrive at the accurate focal length.
PREREQUISITESStudents studying optics, optometry professionals, and anyone interested in understanding vision correction methods for hyperopia.
It should be on the opposite side, so q is negative,right? That would give the right answer.TSny said:In order for the person to be able to clearly see an object placed 25 cm away, where should the image of the object formed by the lens be located? Should the image be on the same side of the lens as the object?
q is negative when the image is on the same side as the object.gungo said:It should be on the opposite side, so q is negative,right? That would give the right answer.