Retinoscopy And Refinement

Question 1

The branch of science that describes how rays of light behave and how we can change their behavior to meet patients needs.

Answer 1

Optics

Question 2

______is the portion of the electromagnetic spectrum that is able to stimulate the photoreceptors of the retina, producing visual sensations

Answer 2

Visible light

Question 3

What are the 2 types of photoreceptors?

Answer 3

Rods and cones

Question 4

Photoreceptor found throughout the retina numbering 125 million and primarily responsible for vision in dim light

Answer 4

Rods

Question 5

Photoreceptor found in macula numbering 6-8 million and is responsible for color vision and sharp central visual acuity in daylight.

Answer 5

Cones

Question 6

Each wave length of light is the distance from …..

Answer 6

Crest of one wave to that of the next.

Question 7

_______is the number of wavelengths passing a given point in one second

Answer 7

Frequency

Question 8

Light travels fastest in a ___

Answer 8

Vacuum
(Approx 3.0x10 to the 8th power or about 186,284 miles per second.

Question 9

The speed of light decreases when it enters a denser medium such as….

Answer 9

Air, water, or glass

Question 10

The more dense the medium the_____the speed of light

Answer 10

Slower

Question 11

Although frequency of light does not change as speed decreases, the wavelength is…..

Answer 11

Shortened

Question 12

The ratio of the speed of light in a vacuum to the speed of light in a denser medium is _______ for that medium.

Answer 12

The index of refraction
(Refractive index =Index of refraction/speed of light in a specific medium)

Question 13

A material’s _______ is based on its own inherent properties, and is important in lens design.

Answer 13

Index of refraction

Question 14

Light rays are a visible portion of the ___

Answer 14

Electromagnetic spectrum

Question 15

Light with shorter wavelengths has a higher_____than light with a longer wavelength.

Answer 15

Frequency

Question 16

The higher the light’s frequency, the more…..

Answer 16

Energy it releases

Question 17

What are some natural light sources?

Answer 17

Most important the sun, lightening, fireflies, forest fires, and others

Question 18

What type of light source is created by man : incandescent light bulbs, neon tubes, lasers, glow sticks

Answer 18

Artificial light

Question 19

This light sources is most of what we se, due to selective absorption of light rays when they strike objects

Answer 19

Reflected light

Question 20

In nature, light rays tend to travel in _____ until they strike an object

Answer 20

Straight lines

Question 21

The concept of ____ describes whether light will diverge or converge

Answer 21

Vergence

Question 22

When light rays leave a single source spread out as they travel away from the source, it is called……

Answer 22

Divergence

Question 23

All natural light is…..

Answer 23

Divergent

Question 24

When light rays from many sources are brought together to a single focal point

Answer 24

Convergence

Question 25

Distant light rays (more than 20 feet away) are considered ____

Answer 25

Parallel

Question 26

When light rays strike and opaque object, the light is ______

Answer 26

Selectively absorbed

Question 27

If all light is absorbed the object will appear…..

Answer 27

Black

Question 28

If no light is absorbed object will appear….

Answer 28

White

Question 29

If only some light is absorbed the colors not absorbed will be …

Answer 29

Reflected