PERCEPTION - the visual sense

What FORM of energy is VISUAL energy? HOW FAST does it travel? What 2 KINDS OF PROPERTIES does it have?

• Form of ELECTROMAGNETIC RADTIATION

  • TRAVELS 186,000 miles/second

1. WAVE properties

2. PARTICLE properties

What 3 PROPERTIES do LIGHT ENERGY WAVES have?

1. Wavelength–horizontal distance between the same point on two successive waves

2. Amplitude (intensity)–vertical height of the wave

3. complexity–interaction of many different waves

What LIGHT WAVE FREQUENCIES (high/low) represent WHICH colors?

1. HIGH frequency = BLUE

2. LOW frequency = RED

What LIGHT WAVE AMPLITUDES (great/small) represent WHICH colors?

1. GREAT amplitude = YELLOW

2. SMALL amplitude = GREEN

What SHAPE is the EYEBALL in? HOW BIG is it (diameter (mm))? 

(almost) complete sphere

• 24mm in diameter

What are the THREE LAYERS in the EYEBALL?

1. Fibrous tunic

2. Middle, Vascular tunic (Choroid Layer)

3. Retina

WHAT (structurally) is the FIBROUS TUNIC?

Hardened surface that protects the eye

WHAT 2 STRUCTURES make up the FIBROUS TUNIC? WHAT (structurally) are they?

1. Sclera: white of eye

2. Cornea: transparent bulge

WHAT 6 STRUCTURES make up the MIDDLE, VASCULAR TUNIC?

1. CHOROID 

2. CILIARY BODY

3. IRIS

4. PUPIL

5. LENS

6. VITREOUS CHAMBER

What (structurally) is the CHOROID?

•  spongy structure with network of blood vessels for nourishment 

• Located in MIDDLE, VASCULAR TUNIC

What does the CILIARY BODY do?

Produces aqueous humor (fluid in the eye)

• Located in MIDDLE, VASCULAR TUNIC

What (structurally) is the IRIS? What do its TWO LAYERS contain?

•  two-layered structure at front of eye

  • Front layer has pigment; 

  • Inner layer contains blood vessels

• Located in MIDDLE, VASCULAR TUNIC

What (structurally) is the PUPIL?

The center of iris

• Located in MIDDLE, VASCULAR TUNIC

What (structurally) is the LENS? What does it PERFORM?

• transparent structure behind iris

  • performs ACCOMODATION ("autofocus" process through changing lens’s shape)

• Located in MIDDLE, VASCULAR TUNIC

What (structurally) is the VITREOUS CHAMBER? HOW MUCH of the eyeball’s VOLUME does it make up?

 fluid-filled region–⅔ total volume

• Located in MIDDLE, VASCULAR TUNIC

What are 4 COMMON PROBLEMS with the LENS?

1. HYPEROPIA (farsightedness) –lens focuses BEHIND retina

2. MYOPIA (nearsightedness) –lens focuses IN FRONT of retina

3. PREBYOPIA–loss of lens elasticity with age  

4. CATARACTS–reduced transparency with age