6. •• A person can just see the print in a book clearly when she holds the book no closer than at arm’s length

(0.45 m from the eyes).

(a) Does she have (1) nearsightedness,

(2) farsightedness, or (3) astigmatism?

Explain.

(b) Which type of lens will allow her to read the text at the normal near point (0.25 m), and what is that lens’s power?