Problem (Section 27-2, Problem 27.4) Approximating a particular eye as a single thin lens 2.70 cm from the retina, nd a person's eye's near-point distance if the smallest focal length their eye can produce is 2.10 cm. Problem: A nearsighted person cannot a read a sign that is more than 5.2 m from their eyes. To deal with this problem, the person wears contact lenses that do not correct their Vision completely. but do allow them to read signs located up to distances of 12.0 m from his eyes. What is the focal length of the contacts? Problem: A farsighted eye has a near point of 210 cm from the eyes. Obtain the focal length of the converging lenses in pair of contact lenses that can be used to read a book held 25.0 cm from the eyes