Vision and light energy (AP psych)

Iris

A ring of muscle tissue that forms the colored part of the eye. It controls the size of the pupil

Pupil

Adjustable opening in the center of the eye through which light passes

Blind spot

Area in the retina where the optic nerve leaves the back of the eye. No vision here is possible

Farsightedness

Can see distant objects more clearly (eyeball may be too short)

Nearsightedness

Can see nearby objects more clearly (eyeball may be too long)

Rods

Detect black, white and grey. Mainly in periphery of retina. Night vision and peripheral vision

Wavelength

Distance from the peak of one light or sound wave to the next. Determines HUE (color) and PITCH (audition)

Cones

Found mainly in the fovea (center of the retina). Color vision and visual activity.

Feature detectors

Nerve cells in the brain to respond to specific features of a visual stimulus, such shape, angle, or movement.

Color consistency

Perceiving familiar objects as having consistent color, even if hanging illumination alters the wavelength reflected by the object

Path of light waves

Rods+cones-bipolar cells-ganglion cells. Ganglion cells come together to form the optic nerves that transmit visual info to the brain.

Visual acuity

Sharpness of vision

Receptor cells

Specialized neurons designed, in case, to transduce light energy into neural impulses

Parallel processing

The ability of the brain to process several aspects of a situation simultaneously

Amplitude

The height of light or sound wave. Determines BRIGHTNESS in vision and LOUDNESS in hearing

Lens

The transparent structure behind the pupil that changes shape (accommodation) to help focus images on the retina.

Opponent process theory

Theory that opposing retinal processes (red-green, yellow-blue, black-white) enable color vision. Some cells are stimulated by one color and inhibited by another

Young-Hemoltz theory

Theory that retina contains three types of cones-- one for red, blue, and green. When combined they produce any color.