Vision Correction Problem Solving (Near Point, Far Point, Lens Power, Myopia, Hyperopia)

Some examples of solving problems involving corrective lenses. Remember, the image distance should always be negative because corrective lenses create a virtual image for you to see. Farsightedness is fixed with converging lenses (with a positive power) and nearsightedness is fixed with diverging lenses (with a negative power).

0:00 - Intro
0:54 - Problem 1
3:08 - Problem 2
4:55 - Problem 3
6:33 - Problem 4
7:51 - Problem 5
9:35 - Problem 6

Problem 1 - Calculate the power of the eye when viewing objects at the greatest and smallest distances possible with normal vision, assuming a lens-to-retina distance of 2.00 cm (a typical value).

Problem 2 - A myopic person sees that their contact lens prescription is -8.1 D. What is their far point?

Problem 3 - A student with hyperopia (farsightedness) has a near point of 140 cm. What power of lens should be prescribed to correct this?

Problem 4 - A student with myopia (nearsightedness) has a far point of 30 cm. What power of lens should be prescribed to correct this?

Problem 5 - A person with a nearsighted eye has near and far points of 16 cm and 25 cm respectively. Assuming a lens is placed 2 cm from the eye, what power must the lens have to correct this condition?

Problem 6 - A person is to be fitted with bifocals. She can see clearly when the object is between 30 cm and 1.4 m from the eye. The upper portion of the bifocals should be designed to enable her to see distant objects clearly. What power should they have? The lower portion of the bifocals should enable her to see objects comfortably at 25 cm. What power should they have?