Exam 27: Optical Instruments

The focal lengths of the objective lens and the eyepiece of a microscope are 0.50 cm and 2.0 cm,respectively,and their separation adjusted for minimum eyestrain is 6.0 cm.If the microscope is focused on a small object,what is the distance between the object and the objective lens?

What power contact lens must be used to correct the vision of a nearsighted person whose far point is 40 cm?

Alice is farsighted and cannot see objects clearly that are closer to her eye than 80.0 cm.What is the refractive power of the contact lenses that will enable her to comfortably see objects at a distance of 25.0 cm from her eyes?