LEARNING GOAL 3.3: DESCRIBE HOW DIFFERENT PARTS OF THE EYE AND BRAIN

COORDINATE IN THE VISION PROCESS.

Vision

Just FYI…

In this lesson and the next, I’m going to give you lots of extra info that you WON’T be tested on – some will help you with your trial, and some is just plain interesting…

The slides with RED titles are fair game for the test; the other slides are just for your benefit

Stations Review

What happened to your pupils when the level of light changed? (station #5)

How readily were you able to detect color in your peripheral vision? (station #6)

Sight – The Basics

Depends on light waves bouncing off the object

The length of the wave determines the color we see

The height of the wave determines how bright the image appears

Sight – The Eye

Sight – The Front of the Eye

Cornea Clear, curved structure that starts to focus light

Pupil Opening that allows light to pass into the eye

Iris Muscle that dilates/contracts (opens/closes) the

pupil, controlling the amount of light that can get in

Lens Focuses light to project the image onto the back of

the eye

Sight – The Back of the Eye

Retina Light-sensitive surface on the back of the eyeball

Rods and Cones Receptor cells that detect light and generate neural

signalsFovea

Point with the most rods/cones; where your vision is best

Optic nerve Fibers that carry signals from the eyes to the thalamus

Blind spot Region of the retina where the optic nerve connects

and there are no rods/cones to detect light

Sight – Nearsightedness and Farsightedness

Nearsightedness: distant images are projected to a point in front of the retina

Farsightedness: nearby images are projected to a point behind the retina

Near and Far Sightedness

Stations Review

When you stared at certain colors for a long time, then looked at a blank paper, what happened? (station #8)

Sight – Seeing in Color

Rods and cones Rods can detect even low levels of light (throughout retina) Cones detect different colors and details (mostly in center)

Trichromatic (three-color) theory All colors are a combination of red, green, and/or blue light Cones can be classified as red, green, or blue

Opponent-process theory Colors are detected in opponent pairs: red/green,

blue/yellow, black/white Stimulating the nerve associated with one color will inhibit

the nerve associated with the opposite color

Color in Peripheral Vision