4.2 Flashcards
What strikes our eyes is not color….
But pulses of electromagnetic energy that our visual system perceives as color
Wavelength
The distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission
Hue
The dimension of color that is determined by the wavelength of light; what we know as the color names, blue, green, and so forth
Intensity
The amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude
Cornea
Protects the eye and bends light to provide focus
Pupil
The adjustable opening in the center of the eye through which light enters
Iris
A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
Lens
The transparent structure behind the pupil that changes shape to help focus images on the retina
Retina
The light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information
Accommodation
The process by which the eye’s lens change shape to focus near or far objects on the retina
The retina doesn’t….
“See” a whole image
Rods
Retinal receptors that vets the black, white, and gray; necessary for peripheral and twilight vision, when comes don’t respond
Cones
Retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations
Optic nerve
The nerve that carries neural impulses from the eye to the brain
Blind spot
The point at which the optic nerve leaves the eye creating a “blind” apt because no receptor cells are located there