help with optical instruments (the eye)

[hibiscus23]

Hello! Um...can anyone help me with this question?

A woman can see clearly with her right eye only when objects are between 40.0 cm and 177 cm away. Prescription bifocals should have what power (in Diopter) so that she can see distant objects clearly (upper part)? Assume that the glasses will be 1.60 cm from the eye.

[Doc Al]

Here's a hint for correcting the nearsightedness. The 177 cm point is called the far point. You have to find out what power lens is needed for an object at infinity to have an image at the far point. You'll need the thin lens equation: 1/f = 1/o + 1/i. (Look it up!)