Visual anatomy and perception

Frequency (Vision)

-High frequency ->short wavelength (blue color)
-Low frequency-> long wavelength (reddish color)

Amplitude(Vision)

-Great Amplitude->tall (bright colors)
-Small Amplitude -> short (dull colors)

Cornea

-eyes clear protective outer layer protecting the pupil and iris
(where light enters first)

Pupil

-small adjustable opening in center of the eye
(light passes through it)

Iris

-Ring of muscle tissue
-Forms the colored portion of the eye
-*controls the size of pupil by expanding and constricting over the pupil*
Light enters the eye through an opening in the iris

Lens

-transparent structure behind the pupil
-changes shape to help focus images on the retina
*accommodations*
-see close objects clear but not far ones

Retina

-along the back of the eye (light-sensitive inner surface)
-contains rods and cones
-transduction
Contains visual receptor cells

What happens in the retina?

-light waves are traduced into neural impulses by rods and cones..then are passed to the cells

Rods

-located on the retinas outer edge
-sensitive in dim light (meaning they work in dim light)
-detect black, white, and gray and are sensitive to movement
-rods are necessary for peripheral/ twilight vision when cones don't respond
*have a low absolute threshold to light*

Cones

-cluster in and around fovea
- function in daylight... becomes unresponsive in dim light
(this is why we cant see color in the dark)
-they detect detail and create color sensations.

Fovea

-central focal point of retina
-area of greatest visual sharpness of focus

Optic nerve

- made of axons and ganglion cells
-leaves through the back of the eye... carries neural impulses from the eye to the thalamus and then to the visual cortex

Blind spot

-point where optic nerve leaves the eye

Young Helmholtz Theory

-3 different types of color receptors (cones)
-red
-green
-blue
-can produce any color

Parallel Processing

-seeing color, shape, depth,and motion of objects at once

How do we see?

-retina processing
-feature detection
-parallel processing
-Reconition

feature detection

-The ability to detect certain types of stimuli, like movements, shape, and angles, requires specialized cells in the brain called feature detectors.