Question

A thin lens has two focal points, one on either side of the lens at equal distances from its center, and should behave the same for light entering from either side. Look backward and forward through a pair of eyeglasses and comment on whether they are thin lenses.

a. They behave as thin lenses for both directions.
b. They behave as thin lenses only when looked forward.
c. They behave as thin lenses only when looked backward.
d. They do not behave as thin lenses in either direction.

Answer 1

Eyeglasses that have two focal points, one on either side, at equal distances from its center, behave as thin lenses in both directions.

Step-by-step explanation:

A thin lens has two focal points, one on either side, at equal distances from its center, and it behaves the same for light entering from either side. When looking backward and forward through a pair of eyeglasses, they will behave as thin lenses in both directions.

This means that the eyeglasses will focus light rays, regardless of the direction they are coming from, and produce clear images for the wearer.

This behavior is due to the symmetry of the lens and its ability to bend light through refraction. Whether light enters the eyeglasses from the front or the back, it will still be refracted and brought to a focus point at the same distance from the lens.