Psoriasis and eczema.
Light.
Light level.
Blue, green, yellow, red, etc.
Light intensity.
Transmission through a light pipe (optical fiber).
Short-wavelength visible radiation.
A specific portion of the electromagnetic spectrum that includes a limited range of wavelengths or frequencies.
A rainbow represents a constant angle from the observer.
Violet appears on the inner part of a rainbow because it has a smaller angle.
Rickets and osteomalacia can benefit from exposure to sunlight.
The luminous environment.
UV, visible, and IR spectrum radiation.
Classifying colors based on lightness, saturation, and hue.
Conservation of energy.
Light inhibits the production of melatonin when it reaches the retina.
A convex mirror is a diverging mirror.
M-cone (more sensitive to green light).
Yes, but they only measure the energy or power of the light waves or the flow of photons, not the amount of light we see.
A perfectly smooth (highly polished) surface.
Red, green, and blue.
Looking directly at the sun for a prolonged period.
Water droplets in the air and low altitude sunlight from behind.
Inadequate lighting level for the task, excessive brightness contrast, and lamp flicker (even when it is not visible).
Photoreceptors are cells in the retina that detect light and convert it into electrical signals.
Light.
It is important for the production of vitamin D in the skin, which is required for the absorption of calcium in the human body.
Contrast.
A concave mirror can produce real or virtual images, depending on the position of the object relative to the focal distance.
Corrections are needed.
The melatonin cycle.
About 10^12 to 1.
The hue is represented by 5P.
Cold air is denser than warm air because it has a greater refractive index.
1000 to 1.
Darkness permits the production of melatonin.
The light ray bends upward and is effectively totally reflected just above the ground.
555 nm (greenish-yellow).
The visual effects of visible light include how it is perceived by the human visual system.
To change its sensitivity to different luminance levels.
Rods.
It causes drowsiness and lowers body temperature.
Approximately 130 cd/m².
Lighting can influence the abilities and behavior of people with Alzheimer's disease.
Angle of incidence equals angle of reflection.
Refraction is the change in direction of a wave passing from one medium to another or from a gradual change in the medium.
Yes, it holds for smooth or rough, curved or straight surfaces on a point by point basis.
A chromaticity diagram.
Lumen (lm).
The amount of light output from a lamp.
To name a color accurately.
Brightness.
Refraction of light rays.
The conversion factor is used to convert radiation energy measured in watts (W) to the amount of visible light measured in lumens (lm).
The peak intensity of a floodlight can be very high, around 10^9 cd (candela).
A naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky.
The three chromaticities of the red, green, and blue additive primaries.
Reflection of light.
People who suffer from photoepilepsy.
It can create illusions by manipulating how light bounces off surfaces.
To accurately replicate human vision.
Afterimages occur when cone cells become overstimulated and fatigued, causing them to lose sensitivity.
A concave mirror is a mirror that converges reflected light.
For red light, the refractive index is 1.51, and for violet light, it is 1.54.
According to a relative sense of bright and dark.
No, no material behaves like this.
The combination of stimuli on the three kinds of cone cells, each with a different spectral sensitivity.
Light travels in a straight path.
About 0.2% of females.
Brightness.
Secondary rainbows are caused by a double reflection of sunlight inside water droplets.
The surrounding cells, which are still fresh, send out strong signals, leading the brain to perceive the opposite colors.
Because they may emit light at different wavelengths, which can affect how bright they appear to the human eye.
The energy of the light stimulus and its wavelength composition (spectrum).
Light.
The cosine law states that the intensity of light is proportional to the cosine of the angle of incidence.
Clouding of the cornea, reddening of the eye, tearing, photophobia, twitching of the eyelids, and a feeling of grit in the eye.
The spectral luminous efficiency, called V(λ).
The frequency stays the same.
By their saturation, as some colors are vivid and some are dull.
Light is a form of energy in the form of electromagnetic waves or photons.
Reddens, sun tan, edema, pain, blistering, peeling of the skin, and sunburn.
Some photons are absorbed in the pigment, increasing its temperature.
Vision.
Vision.
A double rainbow is when both the primary and secondary rainbows are visible.
Lighting and photography (white balance of a photograph).
The wavelength changes.
Purifying air, liquids, and granular materials.
Sunlight exits at an angle of 50 – 53° to form a secondary rainbow.
Different brightness between adjacent areas.
It regulates or modifies the phase and amplitude of the circadian system.
The photopic response curve.
Isaac Newton developed the corpuscular theory, arguing that the perfectly straight lines of reflection demonstrated light's particle nature.
Because blue light is scattered out of the line of sight, leaving red light.
380 nm to 780 nm.
Light level refers to the amount of light present on a surface, such as a desk top.
Yes, another rainbow may be seen from a different viewpoint.
It is associated with skin aging and increases the risk of developing certain types of skin cancer.
Blue, Green, Red
Light flux.
Photopic vision.
Green (G).
Blue
Approximately 1.6 x 10^9 cd/m².
They are distributed in different areas across the retina.
An intermediate state where both cones and rods are active.
Yes, circadian rhythms are self-sustained.
As the ratio of the speed of light in a vacuum to the speed of light in the medium.
Rods, S-cones, M-cones, and L-cones.
Rods are responsible for vision in low light conditions.
Blue light.
It will be totally reflected internally.
Classifying colors according to a relative sense of brightness and darkness.
Red appears on the outer part of a rainbow because it has a larger angle.
Violet, blue, cyan, green, yellow, orange, red.
Light is necessary for the visual system to operate.
The gamut is not large.
Reflection from a perfectly smooth (highly polished) surface that gives a clear and well-defined image.
The lens focuses the image by changing its shape.
Normal incidence refers to light hitting a surface at a 90-degree angle, or perpendicular to the surface.
Eyestrain is the result of prolonged experience of lighting conditions that cause discomfort.
To produce an image of the external world on a layer of photoreceptive cells in the retina at the back of the eye.
Adaptation.
Exposure to light.
Light exchanges its energy in the form of discrete particles.
The human eye can sense a luminance range from 10^-7 to >10^9 cd/m^2.
The International Committee for Weights and Measures.
No, the human eye cannot sense the entire range of luminance at the same time.
To the center of the brain through neural pathways.
By using high light levels at appropriate times.
It is a technical parameter for lighting design specification.
500 lux.
It generates light that reduces the quality of the image.
Light-adapted (photopic vision) and dark-adapted (scotopic vision).
1000:1
When the retinal illuminance is changed, pigment is bleached and regenerated to re-establish equilibrium.
Approximately 400 nm to 780 nm.
The lens.
Less light.
The blind spot is the point where the optic nerve exits the eye, lacking photoreceptors.
Any chromaticity that is within the triangle defined by the primary colors.
Fluctuating light covering a large area and at a high percentage modulation.
Hue, Saturation (or purity), and Brightness (or lightness or value).
Violet light bends more than red light.
Light changes direction.
It is reflected, absorbed, or transmitted.
L-cone (more sensitive to red light).
Candela (cd).
They are values representing the portion of each primary color in a colorimetric system.
The value (brightness) is 4.
Light propagates through space as a continuous wave.
S-cone (more sensitive to blue light).
On a layer of photoreceptive cells in the retina at the back of the eye.
A type of depression related to the time of year, where individuals experience serious mood changes when the seasons change.
It is an important property for understanding how light is distributed.
Convex mirrors are commonly used at hidden road turns and in garages.
Advanced sleep phase.
Red (R), Green (G), and Blue (B).
Monochromatic (single wavelength) light is most saturated.
Young people, the elderly, night-shift workers, and travelers across several time zones.
They convert optical radiation to neural signals.
Black
It is the change in sensitivity due to neural processes, which is fast and operative at moderate light levels.
Plants raise and lower their leaves from day to night.
2.42
The occipital lobe.
The fovea is a small central pit in the retina that provides the clearest vision and is densely packed with cones.
A wide range of wavelengths of the visible spectrum.
Continental blue, apple green, sunflower, scarlet, etc.
Different retinal illuminance.
The overstimulated cells send out only a weak signal, causing the affected colors to remain muted.
Viruses, bacteria, molds, and yeasts.
Long (L-cone), Medium (M-cone), and Short (S-cone).
It is separated into different colors.
Blue light is scattered more than red light.
Classifying colors.
No, our perception of light is only a part of the electromagnetic spectrum.
Cool color.
555 nm.
The internal circadian body clock.
1 watt of light at 555 nm gives an amount of light equal to 1.
A convex mirror provides a wider field of view.
Delayed sleep phase.
We see a mirage because light rays bend upward due to the temperature difference between the warm air near the ground and the cooler air above, creating the illusion of water or a reflective surface.
An afterimage is an effect that occurs when we stare at a particular color for too long, leading to the exhaustion of the cone cells that respond to that color.
Light intensity refers to the strength or concentration of a beam of light.
The amount of light produced at 600 nm is 0.631.
Behind you and lower than approximately 42 degrees.
Approximately 6 x 10^5 cd/m².
Rods, L-cones, M-cones, S-cones.
The relationship between the angles of incidence and refraction when light passes through different media.
Humans need light to see.
It governs daily rhythms, endocrine systems, sleep cycles, and mood.
Light affects the regulation of the endocrine system.
Approximately 120 million.
The optic nerve transmits visual information from the retina to the brain.
Green light.
The combination of intensities of stimuli to the 3 kinds of cone cells.
It is used on TV, monitors, printers, digital cameras, internet, etc.
The speed of light changes.
A color is formed by a mixture of three primary colors (Red, Green, Blue).
A concave mirror is used in make-up or shaving mirrors to produce a virtual, magnified, upright image.
Because many of the genes involved in color vision are on the X chromosome, and males have only one X chromosome while females have two.
It can be injurious to health.
Because it can destroy many types of harmful microorganisms.
Reflection from a rough surface where light is reflected in all directions, resulting in no clear image.
By the kind of color (e.g., red, green, blue) and by hue.
The image is always erect, virtual, and diminished in size.
Luminance is a measure of the brightness of light emitted or reflected from a surface.
1 watt = 683 lumens.
Scotopic vision.
The kind of color, such as red, green, or blue.
Light therapy with sunlight or bright lights ranging from 2,500 to 10,000 lux at the eye.
Cones.
Red
Four photoreceptor types.
Brightness (lightness or value) is related to the amount of reflected or emitted light corresponding to luminance.
Black
Mixing of color paints, color printing, light filters.
No, they have different spectral sensitivity.
Light affects daily rhythms, endocrine systems, sleep cycles, and mood.
Approximately 380 nm to 600 nm.
Light can influence mood positively or negatively.
Cones are responsible for color vision and function best in bright light.
The fovea is a small central pit in the retina that provides the clearest vision.
The temperature of an ideal black body radiator that radiates light of comparable hue to that of the light source.
About 8% of males.
By operating different combinations of retinal photoreceptors at different retinal illuminances.
Light energy, heat energy, and electrical energy.
Through the circular opening called the pupil.
Hue, value (lightness), and chroma (color purity).
Factors such as wavelength, color, and the sensitivity of the human eye to different wavelengths can cause one light source to appear brighter.
Reflection of light.
Light bends toward the normal.
It enables reading of dark words on a light background.
It can damage the tissue.
Melatonin is important for a normal sleep-wake cycle.
The body releases more melanin into the skin's cells, causing the skin color to darken.
Warm color.
As neural signals.
Photopic vision.
Saturation corresponds to the 'purity' of the color or how much the spectrum is distributed across wavelengths.
The 'light level' or available light for a task.
A treatment method that involves exposure to bright lights to address certain medical conditions like Seasonal Affective Disorder (SAD).
Different photopigments.
20 lux.
16 to 1
n1 * sin(θ1) = n2 * sin(θ2)
The photoelectric effect.
A quantum.
How much light is being reflected from a surface.
In one small area that lies on the visual axis of the eye (fovea).
Fine details and rapid changes in image.
Three kinds of cone cells.
The 'Pokémon Shock' incident from the episode 'Dennō Senshi Porygon'.
A color space that specifies colors based on three color dimensions: hue, value (lightness), and chroma (color purity).
The relative efficiency of light detection as a function of the wavelength of the light.
The portion of each primary color (Red, Green, Blue).
A color temperature greater than 5000K.
Light demonstrates both wave and particle nature.
No, it affects human health regardless of whether it stimulates the visual or circadian system.
Saturation.
Oblique incidence refers to light hitting a surface at any angle other than 90 degrees.
A color temperature between 2500K and 3300K.
No, the amount of visible light depends on the strength of stimulation of our visual sensation, which is influenced by wavelength.
A rough surface.
Non-visual effects of visible light include impacts on circadian rhythms and other physiological processes.
Non-visual effects of radiation can include various health impacts not related to vision, such as effects on skin and cellular processes.
Red (R).
Cyan (C).
Black (K).
Rods.
Cone cells.
Rod cells.
Optical radiation entering the eye helps regulate daily rhythms.
Photon.
Rods and cones.
The eyes capture slightly different images from each angle, and the brain combines these images to create a sense of depth and distance.
Kelvin (K).
TV, monitors, printers, digital cameras, internet, etc.
683 lm/W.
Solar radiation.
Water droplets refract and reflect light to the observer.
Amount of light, light level, brightness, and light intensity.
Complex physiological responses.
Operation of the human visual system.
By secreting hormones that synchronize the body clock to a 24-hour cycle.
Within the arc of a circle centered at the eye of the observer.
There are three types of cones, resulting in trichromatic color vision.
5P4/8, where hue is 5P, value is 4, and chroma is 8.
Albert Einstein discovered the photoelectric effect, wherein electrons are emitted from atoms when they absorb energy from light, and the energy received by the electrons is dependent on the frequency of light.
Psychological reasons.
Light behaves both as a wave and a particle.
An afterimage is caused by the exhaustion of the cone cells that respond to a particular color after staring at it for too long.
Green
Magenta (M).
Scotopic vision.
It reduces the adaptation ability of the eye.
The sleep-wake cycle.
1.52
Brightness.
To capture light and convert it into electrical signals for the brain to process.
The brain processes visual information by interpreting electrical signals sent from the retina through the optic nerve.
The optic nerve transmits visual information from the retina to the brain.
By specifying colors based on their hue, value (lightness), and chroma (color purity).
In the retina.
Melanin absorbs solar radiation.
Symptoms include irritation and inflammation of the eyes and lids, blurring or double vision, headaches, indigestion, and giddiness.
Yes, it depends on direction.
Melatonin.
The relative response at 500 nm is 0.323.
It raises the temperature, and if the temperature elevation is sufficient, burns will be produced.
42 degrees.
299,792,458 m/s (~3 x 10^8 m/s).
Difficulty in focusing at near-working distances.
Approximately 8000 cd/m².
It causes a decrease in transparency in the lens.
White (W).
No, all kinds of living things have different changes in behavior that occur regularly over a 24-hour cycle.
Photopic vision.
cd/m² (candela per square meter).
Photopic vision (cones).
Approximately 8 million.
Under bright light.
The visual cortex processes and interprets visual information received from the eyes.
L-cones, M-cones, and S-cones.
Rayleigh scattering.
42 degrees.
The amount of light refers to the total light emitted from a source, such as a lamp.
The chroma (saturation) is 8.
Robert Hooke and other researchers showed by experiments that light is medium-dependent propagation of waves.
It helps synchronize to the local daily light-dark pattern.
Hue refers to the color name such as red, orange, yellow, green, cyan, blue, violet.
Brightness refers to the perceived luminance of an object or surface.
The amount of light produced at 500 nm is 0.323.
Too large luminance variation in a scene can cause discomfort.
The meter is defined in terms of the speed of light (c).
The lens becomes yellow, reducing the short wavelength radiation reaching the retina.
Yellow (Y).
Daily rhythms that repeat approximately every 24 hours and are driven by an internal biological clock.
Reduced visual acuity and reduced contrast sensitivity.
It is the change in sensitivity due to the percentage of unbleached pigment in each photoreceptor.
Several minutes
The surface and the illuminance.
In the outer edges of the retina.
Responsible for night vision.
It represents the weighting factor to match the response of the human eye.
The strength of light.
Radiometer.
A rainbow.
A mirage is an optical illusion caused by the refraction and total reflection of light in layers of air with different temperatures.
Lux (lx).
Having more overlap between green and red regions than usual.
Cyan (C), Magenta (M), Yellow (Y).
They use a filter to cut out overlapping wavelengths, allowing for a clearer distinction between colors, especially red and green.
Approximately 8 x 10^8 cd/m².
A common example of an afterimage is the bright glow that seems to float before one's eyes after looking into a light source for a few seconds.
Blue (B).
The iris constricts and dilates in response to increased and decreased levels of retinal illuminance.
In TV and computer monitors.
Increased prevalence of retinal disease.
Scotopic vision.
<p>E = hv , where h is the Planck constant.</p>
Rods and cones.
Cones are responsible for color vision and function best in bright light.
The brain combines images from both eyes to create a three-dimensional perception of depth.
Color blindness, or color vision deficiency, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions.
Thomas Young’s double-slit experiment.
The 'density' of light incident on a surface.
Albert Einstein’s analysis of the photoelectric effect.
40 degrees.
Cones.
Yes, color is perceived.
1 nm = 10^-9 meters.
Black
In discrete finite amounts (or packets) related to the frequency.
Albert Einstein in 1905.
0.01 cd/m², 0.05 cd/m², 0.4 cd/m², 2 cd/m², 380 cd/m², 2000 cd/m², 2900 cd/m², 15000 cd/m².
To detect light and convert it into electrochemical signals for the brain to process.
The occipital lobe.
Red light.
Three cone photopigments (L-cones, M-cones, and S-cones).
Based on human perception.
The spectral luminous efficiency at 555 nm for photopic vision is 1.000.
Between 380 nm and 780 nm.
Snell's law.
No, there is no perception of color.
1.33
They are adjusted by external cues, commonly the most important of which is daylight.
Light helps regulate sleep cycles.
Rods are responsible for vision in low light conditions.
The brain processes electrochemical signals from the eyes to create a coherent visual representation.
Responsible for color vision.
A fault in the development of one or more sets of retinal cones.
<p>By wavelength (λ) and frequency (v).</p>
<p>Speed = Wavelength x Frequency (c = λ x v).</p>
<p>h=6.626 x 10^-34 Js.</p>
<p>The blind spot is an area on the retina where there are no photoreceptors, so any image that falls on this spot cannot be seen, the image becomes black.</p>
