vision

Transduction

The process by which our sensory systems encode stimulus energy as neural messages.

Wavelength

The distance from the peak of one light or sound wave to the peak of the next.

Intensity

The amount of energy in light waves which influences perceived brightness or loudness.

Cornea

The protective outer layer of the eye that bends light to provide focus.

Iris

The colored muscle surrounding the pupil that adjusts the amount of light entering the eye.

Pupil

The adjustable opening in the center of the eye through which light enters.

Lens

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

Accommodation

The process by which the eye's lens changes shape to focus on near or far objects.

Retina

The light-sensitive inner surface of the eye that contains rods and cones.

Fovea

The central focal point in the retina where cones are densely packed, providing sharp vision.

Acuity

The sharpness of vision.

Rods

Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision.

Cones

Retinal receptor cells concentrated near the center of the retina that function in daylight and give rise to color sensations.

Blind Spot

The point where the optic nerve leaves the eye, lacking receptor cells, creating a gap in vision.

Optic Nerve

The nerve that carries neural impulses from the eye to the brain.

Nearsightedness

A condition where nearby objects are seen clearly but distant objects are blurred because they are focused in front of the retina.

Farsightedness

A condition where distant objects are seen clearly but nearby objects are blurred because they are focused behind the retina.

Hue

The dimension of color determined by the wavelength of light.

Feature Detectors

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

Color Constancy

The ability to perceive familiar objects as having consistent color, even when illumination changes.

Trichromatic Theory

The theory that the retina has three types of color receptors sensitive to red, green, and blue light.

Opponent-Process Theory

The theory that opposing retinal processes enable color vision, with certain cells being stimulated by one color and inhibited by another.

Parallel Processing

The processing of several aspects of a problem simultaneously; the brain's natural information processing method.

Accommodation

The process by which the lens of the eye changes shape to focus images at different distances.

Chemical Changes

Changes occurring in response to light that generate neural signals in rods and cones.

Optic Chiasm

The point where the optic nerves cross, allowing visual information from both eyes to be processed together.

Visual Cortex

The part of the brain located in the occipital lobe that processes visual information.

Pupil Dilation

The process where the pupil enlarges to allow more light to enter the eye.

Color Deficiency

The inability to perceive certain colors, often due to missing or malfunctioning cones.

Spectral Sensitivity

The range of wavelengths that a particular type of receptor cell can respond to.

Afterimages

Perception of a color that occurs after staring at and then looking away from a colored stimulus.

Electromagnetic Spectrum

The range of all types of electromagnetic radiation, including visible light.

Visual Processing

The ways in which the brain interprets and makes sense of visual stimuli.

Light Energy

The type of energy that our visual system converts into neural messages.

Retinal Image

The upside-down image formed on the retina when light rays hit it.

Neural Impulses

The electrical signals that are generated by receptor cells and sent to the brain for interpretation.

Photon

A particle of light that carries electromagnetic energy.

Visual Information Coding

The method by which the retina encodes light into neural signals ready for processing by the brain.

Supercell Clusters

Groups of neurons in the visual cortex that respond to complex visual stimuli.

Complex Patterns

More intricate configurations or arrangements of light that the brain interprets beyond basic stimuli.

Gamma Waves

High-frequency brain waves that are associated with the processing and integration of information.

Visual Perception

The process by which the brain interprets and organizes visual stimuli to make sense of the world.

Light Energy and Chemical Changes

Light energy striking the rods and cones produces chemical changes that generate neural signals.

Ganglion Cells

Nerve cells in the optic nerve that receive visual information from photoreceptors (rods and cones) via intermediary cells known as bipolar cells.

Rods in Low-Light Vision

Rods are sensitive in dim light, with several rods combining their faint energy outputs onto a single bipolar cell to enhance low-light vision.

fMRI

A brain scan technique that measures and maps brain activity by detecting changes in blood flow associated with neural activity.

EEG

a method for recording electrical brain activity by placing electrodes on the scalp.

Mixing Paint Colors

subtracts wavelengths, resulting in black when all three are mixed

Mixing Lights

An additive process where wavelengths from each light combine, resulting in white when mixing all three primary light colors.