Without her contact lenses, a student can focus an object located 0.80 m to infinity from her eyes. The power lens, measured in diopters, is the reciprocal of the focal length, measured in meters. Assuming that the image distance in the eye is 0.02 m, what lens power does she require for reading a text located 0.25 m from her eyes.
D=(1/f), where f is expressed in meters
The Attempt at a Solution
Well, the student's near point is 0.80 m, and the object is at 0.25 m from her eyes.
Thus, (1/f)=(1/-0.8)+(1/0.25) and D=2.75
But how does the image distance in the eye come into play? I don't really know what it means by image distance in the eye. Can someone help?