Visual sense
- 1. Visual Sense (pg 10)
- 2. Layers of the eyeball
- 3. Layers of the eyeball • Fibrous tunic: Outer coat. Consists of cornea (clear) and sclera (white)
- 4. 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)
- 5. 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
- 6. Interior of the Eyeball • Lens: transparent, convex structure that focuses light onto the retina
- 7. 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
- 8. 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)
- 9. 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)
- 10. Photoreceptors • Rods: 120 million. Sensitive to dim light. Only see black and white. Most abundant at edges of retina
- 11. 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
- 12. Pop Quiz! • Hold up “rod” or “cone” sign
- 13. Pop Quiz! 1. Responsible for peripheral vision
- 14. Pop Quiz! 1. Responsible for peripheral vision RODS
- 15. Pop Quiz! 2. Used in moonlight
- 16. Pop Quiz! 2. Used in moonlight RODS
- 17. Pop Quiz! 3. Missing in color-blind people
- 18. Pop Quiz! 3. Missing in color-blind people CONES
- 19. Pop Quiz! 4. If these are damaged you should not drive at night
- 20. Pop Quiz! 4. If these are damaged you should not drive at night RODS
- 21. Pop Quiz! 5. Allows you to see fine detail
- 22. Pop Quiz! 5. Allows you to see fine detail CONES