Session 3

Question 1

What kind of image does a concave lens create and why?

Answer 1

Virtual Image, because the diverging lines never meet so the image is traced backwards

Question 2

What kind of image does a convex lens create and why?

Answer 2

Real Image, because the lens meet after converging behind the lens
(It can also create virtual and no image)

Question 3

What is Diopter?

Answer 3

Unit of a lens refractive power, equal to the reciprocal of the lens focal length in meters.

Question 4

What is focal point?

Answer 4

The distance from the lens to a point of focus.
Minus = -focal length
Plus= +focal length

Question 5

Practice 5 examples of figuring out the focal length and the Diopter Power.

Question 6

What is the Spherical Equivalent and when is it used?

Answer 6

The location halfway between two dioptric values of a spherocylindrical lens.
Used mainly in contact lenses

Question 7

Practice 5 examples of finding the spherical Equivalent