Vision : part 1 Flashcards
Light
A narrow band of electromagnetic radiation that can be conceptualized as a wave or a stream of photons.
Photon
A quantum of visible light (or other form of electromagnetic radiation) demonstrating both particle and wave properties
Light is a waveform when it travels in…
Space
Light is a stream of photons when…
It hits the retina and is transduced in neuronal activity
Frequencies of light and their corresponding color(s)
Shorter wavelengths of light : blue
Medium wavelengths : green or yellow
higher wavelengths : purple or red
Vertically polarized light
When the electric field’s oscillation is restricted to the vertical plane
Every potential angle of polarity is ______ present in most light sources
Equally, so light is unpolarized
Polarizing glasses that only let light pass with a certain ______ can be used to reduce the total amount of light that reaches the retina, as with sunglasses, or to present slightly different visual information to the left and right eye, as with modern 3D glasses.
Polarity
Electromagnetic wave
- The electrical radiation is oscillating in one direction or polarity
- The magnetic field oscillation has a perpendicular polarity to the electrical radiation
Light is usually made up of different rays with different ______
Polarities
Light Scattering
The redirection (deviation from original path) of light as it interacts with particles or molecules in a medium
3 factors in light scattering
1) size
2) shape
3) composition of the particles relative to the wavelength of the light
Rayleigh Scattering
The scattering of light by particles much smaller than the wavelength of light, typically in gases. It causes shorter wavelengths (e.g., blue) to scatter more than longer wavelengths, explaining the blue color of the sky.
Mie Scattering
The scattering of light by particles that are the size of the wavelength of light, like water droplets or dust (larger molecules). Unlike Rayleigh scattering, it affects all wavelengths more equally and often results in a white or grayish appearance, such as in clouds, smog.
Non-Selective Scattering
The scattering of light by particles much larger than the wavelength of light, such as large water droplets in fog. It affects all wavelengths equally, creating a uniform, white appearance.
Light Absorption
The process by which light energy is taken up by a material, converting it into other forms of energy, such as heat (e.g. when the sun hits our skin, it ceases to exist as light and we no longer see it), rather than being transmitted or reflected.
Light Reflection
The process by which light bounces off the surface of a material. Some light get absorbed, some gets reflected.
Specular Reflection
When light reflects off a smooth surface in a single, predictable direction (all the same direction), e.g. still water, mirror
Diffuse Reflection
Where light reflects off a rough surface, scattering in many directions. e.g. desk, clothes
Transmission
The passage of light through a material, where the light continues to propagate without being absorbed or reflected.
Refraction
The bending of light as it passes from one medium to another with a different refractive index, changing its speed and direction.
Cornea
- transparent, dome-shaped outer layer at the front of the eye that helps focus light onto the retina.
- first structure that light encounters as it enters the eye
Anterior Chamber
The fluid-filled space between the cornea and the iris, containing a liquid : aqueous humor, which nourishes the cornea and lens.
Pupil
Circular opening in the center of the iris (colored part of our eye) that regulates the amount of light entering the eye.