1. 3.04 Functions and disorders of the eye
3.04 Understand the functions and disorders of the sensory system

2. 3.04 Understand the functions and disorders of the sensory system
Essential Questions
What are the functions of the sensory system?
What are some disorders of the sensory system?
How are sensory system disorders treated?
How do you relate the body’s communication to the sensory system?
3.04 Understand the functions and disorders of the sensory system

3. Understanding the functions of the eye
Sight
3.04 Understand the functions and disorders of the sensory system

4. Understanding the functions of the eye
External eye
Orbit
Eyelids and eyelashes
Women blink twice as often as men. Why do we blink?
Conjunctiva
Covers, protects
Lacrimal apparatus
Wet, flush debris
Extrinsic muscles
Interesting
tidbit
3.04 Understand the functions and disorders of the sensory system

5. Understanding the functions of the eye
External eye
Extrinsic muscles
Which extrinsic muscle allows you to look upward?
3.04 Understand the functions and disorders of the sensory system

6. Understanding the functions of the eye
Internal eye
Cornea
Protection, focus light
Iris
Adjusts pupil
Pupil
hole
3.04 Understand the functions and disorders of the sensory system

7. Understanding the functions of the eye
Internal eye
Lens
Change focal distance
3.04 Understand the functions and disorders of the sensory system

8. Understanding the functions of the eye
Internal eye
Sclera
Protection from injury
Retina
Receive light, convert to neural signals
3.04 Understand the functions and disorders of the sensory system

9. Understanding the functions of the eye
What is the macula?
Tiny spot at center of retina
Responsible for sharp, clear, central vision
3.04 Understand the functions and disorders of the sensory system

10. Understanding the functions of the eye
Process of Seeing
Trace the field of vision.
Is there anything strange about this picture? Explain
Why can’t you see in the dark?
3.04 Understand the functions and disorders of the sensory system

11. Understanding the functions of the eye
Vision
What happens as you move your paper away from and
toward to your eye?
3.04 Understand the functions and disorders of the sensory system

12. Rods and cones of the retina
Understanding the functions of the eye
Rods and cones of the retina
What are the functions of the rods and cones?
3.04 Understand the functions and disorders of the sensory system

13. 3.04 Understand the functions and disorders of the sensory system
Check your knowledge!
3.04 Understand the functions and disorders of the sensory system

14. 3.04 Understand the functions and disorders of the sensory system
Vision Activity
Do you see what I see?
3.04 Understand the functions and disorders of the sensory system

15. Disorders of the eye Presbyopia Astigmatism Glaucoma
Diabetic retinopathy
Detached retina
Hyperopia
Color blindness
Cataract
Myopia
Conjunctivitis
Have you heard of these conditions?
What do you know about them?
3.04 Understand the functions and disorders of the sensory system

16. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Cataract
Clouding of the lens of the eye
-can be congenital or due to aging or trauma
3.04 Understand the functions and disorders of the sensory system

17. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Cataract
s/s: diplopia, halos around light, clouded/blurred vision, sensitivity to light/glare
Treatment: surgery (remove lens, replace with artificial lens)
3.04 Understand the functions and disorders of the sensory system

18. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Color blindness
Do you see the number?
What is color blindness? -reduced ability to differentiate color
True color blindness is rare
Ishihara chart
3.04 Understand the functions and disorders of the sensory system

19. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Color blindness
Causes: Genetics, diseases, (diabetes, glaucoma, macular degeneration, etc.), medications, aging
More common in males than females
Treatment: none
Ishihara chart
3.04 Understand the functions and disorders of the sensory system

20. How is conjunctivitis spread?
Disorders of the eye
How is conjunctivitis spread?
How can it be prevented?
Conjunctivitis
What is conjunctivitis?
s/s: redness, itchy eyes, sensation of foreign object, discharge during sleeping, tearing
Causes: direct contact with infected fluids
Treatment: Medication
3.04 Understand the functions and disorders of the sensory system

21. 3.04 Understand the functions and disorders of the sensory system
Detached retina
Retina pulls away from the blood vessels supplying oxygen and nutrients
-emergency medical condition potentially leading to blindness
3.04 Understand the functions and disorders of the sensory system

22. 3.04 Understand the functions and disorders of the sensory system
Detached retina
s/s: sudden appearance of floaters, flashes of light, or shadow over portion of visual field
Causes: injury, advanced diabetes, inflammatory eye disorder
Treatment: Surgery, but not guaranteed
3.04 Understand the functions and disorders of the sensory system

23. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Diabetic retinopathy
Causes: too much sugar can lead to blockage of vessels
s/s: floaters, blurred/fluctuating/ impaired vision, dark spots, vision loss
Treatment: Surgery to reattach
3.04 Understand the functions and disorders of the sensory system

24. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Glaucoma
Damage to optic nerve; increased pressure
s/s: patchy blind spots, severe HA, eye pain, n/v, blurred vision, halos
Tonometry
3.04 Understand the functions and disorders of the sensory system

25. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Glaucoma
Treatment: prescription eye drops, surgery
Prevention: regular eye exams, know family history, exercise, eye protection
Tonometry
3.04 Understand the functions and disorders of the sensory system

26. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Macular degeneration
Inability to focus due to degeneration
Compare the two types.
Wet-blood vessels leak into surrounding tissue
Dry-macula thins, breaks down
3.04 Understand the functions and disorders of the sensory system

27. 3.04 Understand the functions and disorders of the sensory system
Disorders of the eye
Macular degeneration
How is it diagnosed?
Test for defects in central vision, fluorescein angiogram, exam of the back of eye (pressure)
What is the treatment?
laser surgery, medication, light therapy (photodynamic)
3.04 Understand the functions and disorders of the sensory system

28. Problems with Focus
Compare the symptoms and treatments of these common eye disorders.
Can a person have more than one of these disorders? Explain.
3.04 Understand the functions and disorders of the sensory system

29. What is the difference between an ophthalmologist and an optician?
Testing vision
How do we test visual acuity?
What is 20/20?
What does PERRLA mean?
What is the difference between
an ophthalmologist and an optician?
3.04 Understand the functions and disorders of the sensory system

30. 3.04 Understand the functions and disorders of the sensory system
Essential Questions
What are the functions of the sensory system?
What are some disorders of the sensory system?
How are sensory system disorders treated?
How do you relate the body’s communication to the sensory system?
3.04 Understand the functions and disorders of the sensory system

31. 3.04 Functions and disorders of the eye
The End
3.04 Understand the functions and disorders of the sensory system