Silas is farsighted and wants to read the newspaper. Withoutglasses, Silass near point (the closest point he
Question:
Silas is farsighted and wants to read the newspaper. Withoutglasses, Silas’s near point (the closest point he can see in focus)is far away, so he has to try to read the paper by holding his armsoutstretched. With his glasses, which have a prescription of PS =+2.75 D, he can hold the paper closer because the glasses make animage at the distance his unassisted eye can focus.
(A) Given the function of prescription lenses, what are thesigns (+or?) for do and Explain.
(B) If his glasses let him hold the paper at 25 cm away from hiseyes, and the glasses sit 2.0 cm away from his eyes, what is hisnear point without glasses? Draw a diagram that includes the lens,eye, object, and image.
(C) He can’t find his glasses so he borrows Ethel’s with aprescription of PE = +1.75 D, and a gap of 2.0 cm between his eyesand the lenses. When he wears Ethel’s glasses, how close to his eyecan he bring the newspaper and still see it clearly?
International Marketing And Export Management
ISBN: 9781292016924
8th Edition
Authors: Gerald Albaum , Alexander Josiassen , Edwin Duerr