1. Special Senses—Eyes Chapter 11

2. Introduction

3. Each eyeball contains three distinct tunics (layers):
11 SPECIAL SENSES—EYES
Each eye is globe-shaped and located within a hollow bony socked (orbit) in the anterior cranium.
Each eyeball contains three distinct tunics (layers):
Outermost layer, the fibrous tunic.
Sclera
cornea
conjunctiva. 3

4. Supporting structures
Eyelid and lacrimal glands.
Eyelids and eyelashes
Lacrimal gland
Lacrimal ducts
Nasolacrimal duct
Drains tears from lacrimal sac to the nasal cavity. 4

5. Supporting structures of the eye
Eyelids and eyelashes protect eyes and prevent foreign substances from entering.
Lacrimal glands continuously secrete tears that travel through lacrimal ducts.
Nasolacrimal duct drains tears from lacrimal sac to the nasal cavity. 5

7. ocul/o, ophthalm/o: eye blephar/o: eyelid opt/o: eye, vision
Combining Forms – p
ocul/o, ophthalm/o: eye
blephar/o: eyelid
opt/o: eye, vision
retin/o: retina

8. Combining Forms
choroid/o: choroid
irid/o: iris
corne/o: cornea

9. dacry/o, lacrim/o: tear dipl/o: double kerat/o: hard tissue
Combining Forms
dacry/o, lacrim/o: tear
dipl/o: double
kerat/o: hard tissue
cor/o, core/o, pupill/o: pupil

10. Suffixes
-opia, -opsia: vision
-ptosis: prolapse, drooping
-tomy: incision
-tropia: turning

11. Build Medical Words
pertaining to within the eye: /o/ /ar 11

12. Build Medical Words
pertaining to within the eye: intra/ocul/ar

13. Build Medical Words prolapse of the eyelid: disease of the retina:
inflammation of the conjunctiva:
Pedagogical Note: Have students place a slash between each word element to identify the word parts and combining vowels. 13

14. Build Medical Words prolapse of the eyelid: blephar/o/ptosis
disease of the retina: retin/o/pathy
inflammation of the conjunctiva: conjunctiv/itis

16. Pathology of the Eye

17. Cataract Opacity or clouding of the lens or its surrounding membrane.
Unilateral or bilateral.
Slow development affecting visual acuity.
Especially common in older persons.
Cataract as shown in left eye.

18. Treatment Cataract Depends on degree of visual impairment.
Depends on age, general health, and occupation of the individual.
Glasses for mild cases. Surgery when vision is impaired.
Surgical extraction of defective lens. 18

19. Strabismus Signs and Symptoms
Visual defect in which both eyes cannot be directed to focus simultaneously on the same object.
Defect may affect one or both eyes.
There are two types: esotropia and exotropia.
With either form, the main symptom is diplopia. 19

21. Signs and Symptoms Strabismus Esotropia
(continued)
Esotropia
Eye turns inward; also called cross-eye.
Type of strabismus - Esotropia 21

22. Signs and Symptoms Strabismus Exotropia
(continued)
Exotropia
Eye turns outward; also called wall-eye.
Pedagogical Note: You may add other disorders to this presentation and insert illustrations from the Image Bank. Just visit Medical Terminology Simplified online resource center at DavisPlus or other resources for appropriate illustrations and information.
Type of strabismus - Exotropia 22

23. Glaucoma

24. Glaucoma https://www.youtube.com/watch?v=TgjdPgSxeYg
Signs and Symptoms
Accumulated fluid pressure within the eye damages the retina and optic nerve, often causing blindness.
Common forms develop asymptomatically.
Eye showing normal flow of aqueous humor (yellow arrows) and abnormal flow (red arrows). 24

25. Glaucoma Signs and Symptoms (continued)
Often not detected until irreparable damage occurs to retinas or optic nerves.
When symptoms appear late, they may include aching eyes and visual disturbances such as seeing halos around lights or a noticeable loss of peripheral vision.
Glaucoma. Destruction of optic nerve (black arrows). 25

26. Macular Degeneration Signs and Symptoms
Macula, small area of retina responsible for central and color vision as shown in the eye.
Macula and retina 26

27. Stye Signs and symptoms
Inflammatory infection of sebaceous glands of the eyelid.
Pain, swelling, redness, and formation of pus at the site.
Hordoleum (stye) 27

28. Vocabulary Challenge Exercise
achromatopsia: congenital deficiency in color perception; also called color blindness
astigmatism: defective curvature of the cornea and lens resulting in a distorted image 28

29. Vocabulary Challenge Exercise
Conjunctivitis
diabetic retinopathy 29

30. Vocabulary Word Challenge
conjunctivitis: inflammation of the conjunctiva that can be caused by bacteria, allergy, irritation, or a foreign body; also called pinkeye
diabetic retinopathy: occurs in people with diabetes, manifested by small hemorrhages, edema, and formation of new vessels leading to scarring and eventual loss of vision

31. 11 SPECIAL SENSES—EYES Vocabulary Challenge Exercise
photophobia:
retinal detachment: 31

32. Vocabulary Word Challenge
photophobia: unusual intolerance and sensitivity to light
retinal detachment: separation of the retina from the choroid, which disrupts vision and results in blindness if not repaired

33. Diagnostic Procedures
Visual acuity test
Visual acuity is measured with use of a Snellen chart.
Imprinted with alphabetical letters graduating in size from the smallest (bottom) to the largest (top)
Patient is positioned 20 feet from the chart.
Snellen chart 33 33

34. Diagnostic Procedures
Visual acuity test (continued)
Examiner has the patient cover one eye with a 3 x 5 card or eye cover.
Patient then reads out loud an indicated line of letters.
Lowest line on the chart that the patient is able to read accurately is used to indicate visual acuity for that eye.
Each eye is tested individually.
Snellen chart 34 34

35. Diagnostic Procedures
Visual acuity test (continued)
Normal vision is 20/20, which means the patient can read at 20 feet what the normal eye can read at 20 feet.
Visual impairment occurs at 20/70.
Legal blindness occurs at 20/200 or more with correction. 35 35

36. Build Medical Words inflammation of the retina: fear of light:
paralysis of the eye: 36

37. Build Medical Words inflammation of the retina: retinitis
fear of light: photophobia
paralysis of the eye: ophthalmoplegia

38. Pharmacology Antiglaucoma drugs
Reduce IOP by lowering amount of aqueous humor in the eyelid, reducing its production, or increasing the outflow.
Miotics
Cause pupils to constrict.
Increase outflow of eye fluids. 38

39. Mydriatics Pharmacology Cause pupils to dilate.
Used to prepare eyes for internal examination. 39