D2- Theoretical Optics, Ophthalmics, & Contact Lens Flashcards
1
Q
Branches of optics:
A
Geometrical optics
Physical optics
Quantum optics
2
Q
Branch of optics that deals with the study of light in terms of ray
A
Geometrical optics
3
Q
Branch of optics that deals with the study of light in a form of waves
A
Physical optics
4
Q
Branch of optics that deals with the interaction of light with atomic entities of matter
A
Quantum optics
5
Q
Object or bodies that are capable of emitting their own light either naturally or artifically
A
Source of light
6
Q
Light sources that cannot be controlled by man (eg. sun, stars, bioluminescent)
A
Natural sources
7
Q
Light sources that can be controlled by man (eg. candles, fire, electricity)
A
Artificial sources
8
Q
A source of light that is either infinitely small
A
Point source
9
Q
A source of light that has a measurable area consists of infinite number of point sources
A
Extended sources
10
Q
4 theories of light
A
Emission Theory
Undulatory Theory
Electromagnetic Theory
Quantum Theory
11
Q
Light is composed of minute particles of matter called
A
Corpuscle
12
Q
The bouncing back of light
A
Reflection
13
Q
Bending of light
A
Refraction
14
Q
Transformation of light into some other form of energy
A
Absorption
15
Q
Decomposition of light into its constituent elements by refraction through medium whose surface are not parallel
A
Dipsersion
16
Q
Slight bending of light around the corners
A
Diffraction
17
Q
The process of restricting the vibration directions of the electromagnetic wave to only one direction
A
Polarization
18
Q
The most common method of polarization involves the use of _____
A
Polaroid filter
19
Q
A type of medium or body where light passes through it freely, with minimum absorption and reflection
A
Transparent medium
20
Q
A type of medium or body which transmit only a portion of light such as a frosted glass
A
Translucent medium
21
Q
A type of medium or body where all the rays of light incident on it are either absorbed or reflected that none traverse it
A
Opaque medium
22
Q
Those of shorter wavelength than violet are known as
A
Ultraviolet radiation
23
Q
Those of longer wavelengths than red are known as
A
Infra-red or thermal radiation
24
Q
A law that states that for radiation to have effect on a substance through which it travels, it must be absorbed by the substance
A
Draper’s Law
25
A heating effect, raising the molecule from the resting state to an excited state
Thermal effect
26
A disease in the retina which is caused by looking directly at a solar eclipse
Solar retinopathy
27
Exposure to short ultraviolet for 30 min.-24 hrs. can cause what?
Photo-ophthalmia
Photokeratitis
Photo-conjunctivitis
28
Exposure to long ultraviolet may cause what?
Yellow coloration of the lens nucleus
29
Visible light spectrum wavelength of VIOLET
390-446 nm
30
Visible light spectrum wavelength of BLUE
446-500 nm
31
Visible light spectrum wavelength of GREEN
500-560 nm
32
Visible light spectrum wavelength of YELLOW
560-592 nm
33
Visible light spectrum wavelength of ORANGE
592- 650 nm
34
Visible light spectrum wavelength of RED
650-780 nm
35
A special source of light of only one pure color
Laser
36
The law that states that “in a homogenous optical medium, light travels along a straight path”
Law of Rectilinear Propagation of Light
37
The region of partial shadow, which receives light from only a portion of the source
Penumbra
38
Dark image formed by intercepting light rays; formed if you block the rays of light
Shadow
39
The region of complete shadow formed on the screen
Umbra
40
The natural phenomenon that illustrates the formation of shadows
Eclipses
41
The science of measuring and comparing light quantities
Photometry
42
An instrument used for measuring and comparing light quantities
Photometer
43
Photometry are concerned with three aspects:
Luminous flux
Luminous intensity
Illuminance or brightness
44
Rate of flow of luminous energy from a source
Luminous flux
45
Radiant energy which is emitted by a source per unit time which causes the sensation of sight
Luminous flux
46
The unit of luminous flux
Lumen
47
The quantity of light emitted by a source in one given direction
Luminous intensity
48
The unit of luminous intensity
Candle
49
Luminous intensity is generally referred to as
Candle power
50
Measure of the illumination
Illuminance
51
A law that states that the illumination of a surface placed perpendicularly to the direction in which the light is traveling varies as the distance of the surface from the source
Inverse square law
52
Types of reflection
Specular reflection
Diffuse reflection
53
A type of reflection that occurs only on smooth surface such as glass, mirror or mercury
Specular reflection
54
A type of reflection which occurs only on rough surfaces.
Diffuse reflection
55
A type of reflection where reflected rays travel in the same direction
Specular reflection
56
A type of reflection where reflected rays spread out in different directions
Diffuse reflection
57
Line passing through the center of the sphere and attaching to the mirror in the exact center of a mirror
Principal axis
58
The point in the center of sphere from which the mirror was sliced
Center of curvature
59
The point on the mirror’s surface where the principal axis meets the mirror
Vertex
60
Midway between the vertex and the center of curvature
Focal point
61
Distance from the vertex to the center of curvature
Radius of curvature
62
Distance from the mirror to the focal point
Focal length
63
Bending of light as it goes from one medium to another of different density
Refraction
64
A type of index of refraction where the ratio of the speed of light is in empty space to some other optical medium
Absolute index of refraction
65
A type of index of refraction where the ratio of the speed of light of 2 optical media is neither air or light that doesn't originate in air
Relative index of refraction
66
Index of refraction for vacuum
1.0000
67
Index of refraction for air
1.0
68
Index of refraction for water
1.33
69
Index of refraction for ethyl alcohol
1.36
70
Index of refraction for crown glass
1.523
71
Index of refraction for polycarbonate
1.58
72
Index of refraction for diamond
2.417
73
A portion of transparent substance bounded by two polished surfaces both of which may be curved
Lens
74
Tend to produce convergence of light
Convex
75
Tend to make light divergent
Concave
76
A wedge-shaped portion of a refracting medium contained between two plane polished surfaces which are not parallel to each other
Prism
77
Lens that is thicker at the center than at edge
Convex
78
Lens that forms a magnified image of an object held within its focus
Convex
79
Lens that diminishes the apparent size of an object seen through it
Concave
80
Lens that is thinner at center than at edge
Concave
81
A form of lens where the back surface is plane, all the power being provided by the front surface
Plano conv/conc
82
A form of lens where both surfaces have the same curve but of different power
Bi-conv/conc
83
A form of lens where both surfaces have the same curvature and power
Equi-conc/conv
84
A form of lens where the front surface is convex, the back surface is concave
Plus/minus meniscus
85
The line joining the center of curvature of the two spheres or lens
Optic axis
86
A point through which rays of light pass unrefracted
Optic center
87
Line drawn perpendicular to the optic axis passing through the optic center
Principal of bending plane
88
Defined as changing the form of lens prescription without changing its value
Transposition
89
Two types of transposition
Flat transposition
Toric transposition
90
Process of finding the power or strength of the refracting elements which make up an unknown lens
Neutralization
91
An instrument used to measure the thickness of a lens
Caliper
92
Instrument most commonly used to measure the vertex power of lenses
Lensmeter
93
Other term for lensmeter
Focimeter and Vertometer
94
An amorphous substance made primarily of silica fused at high temperatures with borates or phosphates
Glass
95
A glass material made of dark, volcanic glass that forms when lava cools rapidly
Obsidian
96
A glass material made of hard tube, glassy material formed by lightning striking hand
Fulgurite
97
A glass material made of glassy objects thought to be a result of meteoritic impact on either the earth or the moon
Tektite
98
The degree to which a given lens material will disperse light
Abbe value
99
Color of chromium
Green
100
Color of cobalt
Blue
101
Color of nickel
Violet/brown
102
Color of selenium
Red
103
Color of iron
Green
104
Color of manganese
Deep amber
105
Color of gold
Red
106
Color of antimony
White
107
Who discovered the Emission Theory
Isaac Newton
108
Who discovered the Wave or Undulatory Theory?
Christian Huygens
109
The distance traveled forward by light as it goes through one complete vibration
Wavelength
110
The number of vibration in a given wavelength in one second
Frequency
111
Speed at which vibration travels
Velocity
112
Theory where light was viewed as a particular region of electromagnetic spectrum of radiation
ElectroMagnetic Theory
113
Electromagnetic theory was discovered by
James Clark Maxwell
114
An elemental unit of energy
Quantum
115
The unit of intensity of light on the retina
Photon
116
Elemental unit of light that is made up of single corpuscle from a single point of a light source
Ray
117
Elemental unit of light that is made up of divergent, convergent, and parallel rays
Pencil of light
118
Elemental unit of light that is made up of divergent, convergent, or parallel pencils arising from an extended source
Beam of light
119
Exposure to long infrared can cause what?
Mild cases of conjunctivitis
120
Occurs when the earth enters the shadow cone of the moon
Solar eclipse
121
Occurs when the moon enters the shadow of the earth
Lunar eclipse
122
The visual angle formed at the nodal point of the eye by the object
Apparent height
123
States that the illumination of a surface varies as the cosine of the angle of incidence
Cosine Law of Illumination
124
A thin lens considered to be a medical device placed directly on the surface of the eye
Contact lenses
125
The first to describe the concept of a lens that comes into contact with the eye
Leonardo da Vinci
126
He describe a glass CL designed to match the shape of the eye
John Herschel
127
He describe the first contact lens intended to correct vision
A.E. Fick
128
He designed and fitted glass corneal contact lenses
E. Kalt
129
He fitted a blown glass lens to the eye of a patient whose eye had been surgically removed
F.E. Muller
130
CL used to refractive error, aphakia, and small amount of astigmatism
Spherical contact lens
131
CL for the correction of significant amount of astigmatism
Toric contact lens
132
Gas permeable CL that temporarily reshape the cornea
Ortho-K lens
133
Large diameter CL that have a rigid gas permeable central zone, surrounded by a peripheral zone made of soft or silicon hydrogel material
Hybrid CL
134
Contact lens prototype that monitors glucose levels in tears
Google CL
135
Radius of curvature of the posterior zone
Base curve
136
Posterior central optic portion of the lens
Optic zone
137
A measure of the maximum external dimension of a lens
Lens diameter
138
Quality or state of the material that allows the oxygen to pass through it
Oxygen permeability
139
States how much oxygen goes through the lens
Oxygen transmissibility
140
Minimum EOP for daily wear
12%
141
Minimum EOP for extended wear
8%
142
Physical property of which defines how light rays are affected as they pass through the material
Refractive index
143
A base-down prism that is incorporated into the lens, so that the lens will be heavier at the prism base
Prism ballast
144
A base down prism where the thicker area is closer to the periphery of the lens, away from the optical zone
Peri-ballast
145
Thinnest at the top and bottom edges and thicker in the middle of the lens.
Thin zone
146
This refers to the technique of slicing off the bottom of the lens, to form a “shelf” that will rest upon, and therefore align with the lower eyelid.
Truncation
147
A molecule that includes a positively charged hydrogen ion
Acids
148
A molecule that has negatively charged hydroxide group
Bases
149
Average pH of tearfilm
7.4
150
pH range of contact lens solutions
6.5-8.0
151
A chemical term which describes a solution’s total salt concentration
Osmolality
152
It is the re-writing a cylinder lens formula from one form to another
Flat transposition
153
The graphical representation of the total power of the two principal meridians of a lens
Optical cross
154
Meridian with the highest power
Power meridian
155
Meridian with the lower power
Axis meridian
156
A lens or surface having the same radius of curvature in every meridian
Sphere
157
The standard cylinder axis notation is known as
TABO notation
158
Both lens surfaces are already grounded and polished
Finished
159
Front and back surface are not yet grounded
Rough blank
160
The base curve had been grounded and polished
Semi-finshed
161
What lens material has the thickest lens?
CR-39
162
Refractive index of polycarbonate
1.586
163
Refractive index of trivex
1.53
164
Refractive index of CR-39
1.498
