visual sense

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Visual Sense (pg 10)

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Page 1: Visual sense

Visual Sense (pg 10)

Page 2: Visual sense

Layers of the eyeball

Page 3: Visual sense

Layers of the eyeball• Fibrous tunic: Outer coat. Consists of cornea

(clear) and sclera (white)

Page 4: Visual sense

Layers of the eyeball• Fibrous tunic: Outer coat. Consists of cornea

(clear) and sclera (white)• Vascular tunic: Middle layer. Contains many

blood vessels. Consists of choroid (dark brown layer that absorbs excess light) and iris (colored part of the eye. Doughnut shaped. Has muscles that constrict or dilate the iris to change the size of the pupil)

Page 5: Visual sense

Layers of the eyeball• Fibrous tunic: Outer coat. Consists of cornea

(clear) and sclera (white)• Vascular tunic: Middle layer. Contains many

blood vessels. Consists of choroid (dark brown layer that absorbs excess light) and iris (colored part of the eye. Doughnut shaped. Has muscles that constrict or dilate the iris to change the size of the pupil)

• Retina: Inner layer. Lines the posterior ¾ of the eyeball. Contains photoreceptors

Page 6: Visual sense

Interior of the Eyeball• Lens: transparent, convex structure that

focuses light onto the retina

Page 7: Visual sense

Interior of the Eyeball• Lens: transparent, convex structure that

focuses light onto the retina• Ciliary muscle: Alters the shape of the lens for

viewing objects up close or at a distance

Page 8: Visual sense

Interior of the Eyeball• Lens: transparent, convex structure that

focuses light onto the retina• Ciliary muscle: Alters the shape of the lens for

viewing objects up close or at a distance• Anterior cavity: space anterior to the lens.

Filled with aqueous humor (watery)

Page 9: Visual sense

Interior of the Eyeball• Lens: transparent, convex structure that

focuses light onto the retina• Ciliary muscle: Alters the shape of the lens for

viewing objects up close or at a distance• Anterior cavity: space anterior to the lens.

Filled with aqueous humor (watery)• Vitreous chamber: large cavity behind the

lens. Filled with vitreous humor (jelly-like)

Page 10: Visual sense

Photoreceptors

• Rods: 120 million. Sensitive to dim light. Only see black and white. Most abundant at edges of retina

Page 11: Visual sense

Photoreceptors

• Rods: 120 million. Sensitive to dim light. Only see black and white. Most abundant at edges of retina.

• Cones: 6 million. 3 types: blue, green, and red. Stimulated by brighter light. Allows color vision. Most abundant at the fovea centralis, a point at the center of the retina where images are sharpest

Page 12: Visual sense

Pop Quiz!

• Hold up “rod” or “cone” sign

Page 13: Visual sense

Pop Quiz!

1. Responsible for peripheral vision

Page 14: Visual sense

Pop Quiz!

1. Responsible for peripheral vision

RODS

Page 15: Visual sense

Pop Quiz!

2. Used in moonlight

Page 16: Visual sense

Pop Quiz!

2. Used in moonlight

RODS

Page 17: Visual sense

Pop Quiz!

3. Missing in color-blind people

Page 18: Visual sense

Pop Quiz!

3. Missing in color-blind people

CONES

Page 19: Visual sense

Pop Quiz!

4. If these are damaged you should not drive at night

Page 20: Visual sense

Pop Quiz!

4. If these are damaged you should not drive at night

RODS

Page 21: Visual sense

Pop Quiz!

5. Allows you to see fine detail

Page 22: Visual sense

Pop Quiz!

5. Allows you to see fine detail

CONES