# Eye focusing

by haxxorboi
Tags: focusing
 P: 24 1. The problem statement, all variables and given/known data Suppose the lens in a human eye has far focal length equal to f0 = 40.1 mm, for distant objects to be in focus. A. An object K is 1.69 m from the lens. How much should the focal length change to focus on the object K? B.What is the magnification ( = image size divided by object size) for the object K? 2. Relevant equations 1/di+1/do=1/f 3. The attempt at a solution A. 1/1690+1/x=1/40.1 x=41.0746 mm Thus, delta f = .9746 mm but that's wrong for some reason... but it's been a long week... B. -f2/f1=M Can someone help me out here?
HW Helper
Thanks
P: 26,148
 Quote by haxxorboi 1/1690+1/x=1/40.1 … it's been a long week...
Hi haxxorboi!

Shouldn't the 1/x be on the other side?
 P: 24 *sigh* Yep, that'd be the issue... need either more sleep or more caffeine I guess... Problem solved. Thank you very much... I'm gonna go take a nap...

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