7 PRIMER (ENTOPTIC PHENOMENON, COLORS) Flashcards
Refers to visual perceptions that are produced or influenced by the structures of one’s own eye.
- Entoptic Imagery (entoptic Phenomenon)
- Color vision
Entoptic Imagery (entoptic Phenomenon)
“produced by the structures of own eye”
opacities of the ocular media
- pathologic imperfections
- physiologic imperfections
pathologic imperfections
Under some conditions colored halos can be seen to surround small white lights that are viewed from a distance
- Physiologic and pathologic halos
- Vitreoretinal sources of entoptic images
Physiologic and pathologic halos
chromatic dispersion of white light by various layers of cells in the ocular media.
- Physiologic and pathologic halos
- Vitreoretinal sources of entoptic images
Physiologic and pathologic halos
radial arrangement of lens fibers, which act as diffraction grating
- Physiologic halos
- Pathologic halos
Physiologic halos
increase IOP, radiation keratopathy
- Physiologic halos
- Pathologic halos
Pathologic halos
consisting of flashes of light that were likened to the appearance of flashes of lightning
- Moore’s Lightning Streaks
- Purkinje Figures
Moore’s Lightning Streaks
“flashes of light”
Associated with stress
- Moore’s Lightning Streaks
- Purkinje Figures
Moore’s Lightning Streaks
“stress”
Images of the retinal blood vessels.
- Moore’s Lightning Streaks
- Purkinje Figures
Purkinje Figures
“retinal blood vessels”
Illumination of the fundus by parallel rays of light will allow visualization of small opacities located close to the retina.
- Moore’s Lightning Streaks
- Purkinje Figures
Purkinje Figures
“visualization of small opacities”
Scheerer’s Phenomenon
- Blue field phenomenon
- Phosphene
Blue field phenomenon
appearance of tiny bright dots moving rapidly along squiggly lines in the visual field.
- Blue field phenomenon
- Phosphene
Blue field phenomenon
“bright dots moving”
caused by white blood cells moving in the capillaries in front of the retina
- Blue field phenomenon
- Phosphene
Blue field phenomenon
“white blood cells moving”
is the perception of light without light actually entering the eye
- Blue field phenomenon
- Phosphene
Phosphene
“perception of light without light”
Results from stimulation of retinal ganglion cells
- Blue field phenomenon
- Phosphene
Phosphene
“retinal ganglion cells”
brought by rapid movement of the eye
- Flick phosphene
- phosphene
Flick phosphene
produced by snneze, laughter, a heavy and deep cough, and blowing of the nose
- Flick phosphene
- phosphene
phosphene
Electrical stimulation of the brain
- Flick phosphene
- phosphene
phosphene
refers to an image continuing to appear in one’s vision after the exposure to the original image has ceased
- Afterimage
- Science of Color
Afterimage
Over stimulation of cones
- Negative
- Positive
Negative
Opposite color of the original object
- Negative
- Positive
Negative
Transmission of impulse from the retina to the brain in a dark adapted eye
- Negative
- Positive
Positive
Same color as the original color
- Negative
- Positive
Positive
That aspect of things that is caused by differing qualities of the light reflected or emitted by an object, definable in terms of the observer.
- Afterimage
- Colors
Colors
That aspect of things that is caused by differing qualities of the light reflected or emitted by an object, definable in terms of the observer.
- Afterimage
- Colors
Colors
That aspect of things that is caused by differing qualities of the light reflected or emitted by an object, definable in terms of the observer.
- Afterimage
- Colors
Colors
That aspect of things that is caused by differing qualities of the light reflected or emitted by an object, definable in terms of the observer.
- Afterimage
- Colors
Colors
That aspect of things that is caused by differing qualities of the light reflected or emitted by an object, definable in terms of the observer.
- Afterimage
- Colors
Colors
The characteristics of light by which the individual is made aware of objects or light sources through the receptors of the eye, described in terms of dominant wavelength, luminance, and purity.
- Colors
- Entoptic Phenomenon
Colors
Sometimes called Chromatics, colorimetry, or simply color science
- Science of Color
- Entoptic Phenomenon
Science of Color
When the wavelength is within 390 nm to 700 nm the human eye can perceive it.
- Physics of Color
- Spectral Colors
Physics of Color
Most light sources emit light at many different wavelengths
- Physics of Color
- Spectral Colors
Physics of Color
a color that is evoked by a single wavelength of light in the visible spectrum, or by a relatively narrow band of wavelengths
- Physics of Color
- Spectral Colors
spectral color
The ________ depends on both the physics of the object relative to its environment and the characteristics of the perceiving eye and brain
- color of an object
- Prurkinje effect
color of an object
The ________ depends on both the physics of the object relative to its environment and the characteristics of the perceiving eye and brain
- color of an object
- Prurkinje effect
color of an object
A viewers perception of color also is dependent on the persons contextual cues. (color constancy)
- color of an object
- Prurkinje effect
color of an object
is a process that allows the brain to recognize a familiar object as being a consistent color regardless of the amount of light reflecting from it at a given moment
- Color constancy
- Trichromatic theory
Color constancy
Achieved through a specialized nerve cells in the primary visual cortex called ____
- double opponent cells
- kruithof curve
double opponent cells
“primary visual cortex “
Retinex Theory
- Edwin H. Land
- Thomas Young
- Ewald Hering
Edwin H. Land
Trichromatic Theory
Thomas Young
Opponent Theory of Colors
- Edwin H. Land
- Thomas Young
- Ewald Hering
Ewald Hering
Opponent Theory of Colors
- Edwin H. Land
- Thomas Young
- Ewald Hering
Ewald Hering
he suggest that both the eye and the brain are involve in color constancy
- Edwin H. Land
- Thomas Young
- Ewald Hering
Edwin H. Land (Retinex Theory)
The ability of the human eye to distinguish colors is based upon the varying sensitivity of photoreceptors in the retina particularly the cones to light of different wavelengths.
- Edwin H. Land
- Thomas Young
- Ewald Hering
Trichromatic Theory (Thomas Young)
The ability of the human eye to distinguish colors is based upon the varying sensitivity of photoreceptors in the retina particularly the cones to light of different wavelengths.
- Retinex Theory
- Trichromatic Theory
- Opponent theory of colors
Trichromatic Theory
The ff. is under:
- short wavelength cones / blue cones
- medium wavelength cones / green cones
- long wavelength cones / red cones
- Retinex Theory
- Trichromatic Theory
- Opponent theory of colors
Trichromatic theory (Thomas Young)
most sensitive with wavelengths around 570nm
- short wavelength
- medium wavelength
- long wavelength
long wavelength
most sensitive with wavelengths around 450nm
- short wavelength
- medium wavelength
- long wavelength
short wavelength
- short wavelength
- most sensitive with wavelengths around 540nm
- short wavelength
- medium wavelength
- long wavelength
medium wavelength
- short wavelength
- most sensitive with wavelengths around 450nm
- blue cones
- red cones
- green cones
blue cones
most sensitive with wavelengths around 540nm
- short wavelength
- most sensitive with wavelengths around 540nm
- blue cones
- red cones
- green cones
green cones
- short wavelength
- most sensitive with wavelengths around 570nm
- blue cones
- red cones
- green cones
red cones
In dim light, the ____ are understimulated leaving only the signal from the rods, resulting in a colorless response.
- rods
- cones
cones
“In dim light, colorless response”
These effects are combined and summarized in the _______, that describes the change of color perception, and pleasantness of light as function of temperature and intensity.
- Kruithof curve
- Purkinje effect
Kruithof curve
“pleasantness of light”
The _______ describes a region of luminance levels and color temperatures that are often viewed as comfortable or pleasing to an observer
- Kruithof curve
- Purkinje effect
Kruithof curve
“levels and color temperatures”
The sketch of his curve as presented consists of three major regions:
–> colors are warm and colorful
- lower region
- middle region
- upper region
upper region
The sketch of his curve as presented consists of three major regions:
–> colors are warm and colorful
- lower region
- middle region
- upper region
upper region
The sketch of his curve as presented consists of three major regions:
–> considered pleasing
- lower region
- middle region
- upper region
middle region
The sketch of his curve as presented consists of three major regions:
–> colors that are considered cold and dim
lower region
directly related to human adaptation to changes in illumination
- Purkinje effect
- Kruithof’s findings
Kruithof’s findings
“changes in illumination”
As luminance decreases, the visual system switches from cone-dominated vision to rod dominated
- Purkinje effect
- Kruithof’s findings
Purkinje effect
“switches from cone-dominated vision to rod dominated”
In general, sources of ___________ are all generally considered to be displeasing at low luminance levels
- lower color temperatures
- higher color temperatures
higher color temperatures
“displeasing at low luminance levels”
the ability to distinguish objects based the wavelengths and frequencies of the light they reflect, emit, or transmit
- entoptic phenomenon
- color vision
Color Vision
“distinguish objects based the wavelengths”
The ability to discriminate light on the basis of wavelength composition
- entoptic phenomenon
- color vision
color vision
“discriminate light on the basis of wavelength”
the ability of the eye to perceive differences in the spectral composition of visible light
- entoptic phenomenon
- color vision
color vision
“visible light”
number of rods
120 million
Predominantly located at the peripheral retina
- rods
- cones
rods
Can be triggered by individual photon in optimal condition
- rods
- cones
rods
The adaptation process is slower
- rods
- cones
rods
Lesser visual resolution
- rods
- cones
rods
Better motion sensor
- rods
- cones
rods
Rods has a photopigment called ______
rhodopsin
RODS
Pick of absorption is more on the ________
- shorter wavelength
- longer wavelength
shorter wavelength
what area of the retina a rod-free area?
fovea
Peripheral vision
- rods
- cones
rods
Motion detection
- rods
- cones
rods
Dark-adapted vision (scotopic vision)
- rods
- cones
rods
number of cones
6-7million
Predominantly located at the central retinal
cones
Less sensitive
- rods
- cones
cones
It adapts faster
- rods
- cones
cones
Better visual resolution
- rods
- cones
cones
Sensitive to colors
- rods
- cones
cones
Pick of absorption is more on longer wavelength
- rods
- cones
cones
Central vision
- rods
- cones
cones
Color vision perception
- rods
- cones
cones
Detection of forms and details
- rods
- cones
cones
Light adapted vision (Photopic Vision)
- rods
- cones
cones
