Lab 1

Question 1

A concave lens is a ____ lens

Answer 1

Diverging

Question 2

Concave/Diverging lens

Answer 2

Thinner in the middle and thicker at the edges.
Minifying effect (appear to make things look smaller)
Corrects myopia and is labeled with a -

Question 3

A convex lens is a ___ lens

Answer 3

Converging

Question 4

Convex/Converging

Answer 4

Thicker across middle and thinner at edges.

Corrects hyperion and labeled with a +

Question 5

Cylindrical lens

Answer 5

Has variable power throughout the lens. The power varies uniformly from zero power in one meridian to the maximum dioptric power in the opposite (perpendicular) meridian. The maximum and minimum powers for a particular cylindrical lens are 90 degrees apart.

Question 6

Diopter

Answer 6

The reciprocal of the focal length (in meters) of an optical component and is commonly used in writing ophthalmic prescriptions. Abbreviated as either D, DS (diopters of sphere) or D Cyl (diopters of cylinder).

Question 7

The amount of cylinder is the

Answer 7

difference between the two major meridians

Question 8

How to find the focal length of the lens given the lens power.

Answer 8

100/lens power
Ex: a +1.00 D lens focus parallel light at 100 cm. (100/+1.00= 100 cm)
A +1.50 D lens focuses light at 66.67 cm (100/+1.50)
and a +2.00 D lens focuses light at 50.00 cm. (100/+2.00)

Question 9

Die in a cave.. oh my my

Answer 9

Diverging/concave lens… myopia minus

Question 10

How to find the dioptric power of a lens given the focal length

Answer 10

100/focal length

Question 11

100/focal length=

Answer 11

lens power

Question 12

100/lens power=

Answer 12

focal length

Question 13

shakometry

Answer 13

Hand neutralization. Either will be with or against motion and a plano lens is neutral motion.

Question 14

Does a minus lens go with or against motion

Answer 14

With

Question 15

Does a plus lens go with or against motion

Answer 15

Against

Question 16

When can “with” motion be exhibited from a plus lens?

Answer 16

When the plus lens is held at an eye-to-lens distance greater than the focal length of the lens. In this case, the image is inverted.

Question 17

Why does “with” or “against” motion occur

Answer 17

Due to prismatic displacement. The direction of motion is dependent on the position of the prism’s apex.

Question 18

In a minus (concave) lens, the prisms are __ to ___

Answer 18

Apex to apex

Question 19

In a plus (converging) lens, the prisms are __ to ___

Answer 19

base to base

Question 20

The stronger the lens, the __ the speed of motion

Answer 20

Slower

Question 21

The weaker the lens, the ___ the speed of motion

Answer 21

Faster

Question 22

Lenses that are thinner in the middle and thicker on the edges

Answer 22

Diverging/concave/minus lenses that diverge light.

Myopes uncorrected focus light in front of retina. Diverging lenses diverge light so it focuses on the retina.

Question 23

Lenses that are thicker in the middle and thinner on the edges.

Answer 23

Converging/convex/plus lenses that converge light.

Hyperopes uncorrected focus light behind the retina. Converging lenses converge light so it focuses on the retina.

Question 24

90

Answer 24

The most amount of prescription is in the horizontal meridian.

Question 25

emmetropia

Answer 25

An eye that requires no distance correction