NR 302 EXAM 4 STUDY GUIDE
1. Name the 6 sets of extraocular muscles and the cranial nerve that innervates each one.
a. Abducens nerve (CN VI) – abducts the eye
i. Lateral rectus muscle
b. Troclear nerve (CN IV) – enables to look downward and inward
i. Superior oblique muscles
c. Oculomotor nerve (CN III)
i. Superior rectus muscle
ii. Inferior rectus muscle
iii. Medial rectus muscle
iv. Inferior oblique muscle
2. Name and describe the 3 concentric coats of the eyeball.
a. Sclera (outer layer): tough protective, white covering.
b. Choroid (middle layer): dark pigmentation to prevent light from reflecting
internally. Heavily vascularized to deliver blood to the retina.
c. Retina (inner layer): visual receptive layer of the eye, light waves are changed
into nerve impulses.
3. Name the functions of the ciliary body, the pupil, and the iris.
a. Ciliary body: controls the thickness of the lens.
b. Iris: functions as a diaphragm, varying the opening at its center.
c. Pupil: reacts to amount of ambient light and accommodation, or focusing an
object on the retina.
4. Describe the anterior chamber, the posterior chamber, and the vitreous body.
a. Contains clear, watery aqueous humor produced by the ciliary body. The fluid
delivers nutrients to the surrounding tissues and drain metabolic wastes.
5. Describe how an image formed on the retina compares with its actual appearance in the
outside world.
a. The image formed on the retina is upside down and reversed from the actual
appearance.
6. Describe the lacrimal system.
a. Provides constant irrigation to keep the conjunctiva and cornea moist and
lubricated.
, 7. Define pupillary light reflex, fixation, and accommodation.
a. Pupillary light: normal constriction of the pupils when bright light shines on the
retina.
b. Fixation: a reflex direction of the eye toward an object attracting our attention.
c. Accommodation: the adaptation of the eye for near vision.
8. Concerning the pupillary light reflex, describe and contrast a direct light reflex with a
consensual light reflex.
a. Direct: constriction of the pupil.
b. Consensual: simultaneous constriction of the other pupil.
9. Identify common age-related changes in the eye.
a. Visual acuity diminishes after 50 yr./o.
b. Near vision is affected because of decreased power of accommodation after 40
yr./o and may have blurred vision and difficulty reading.
c. Requires more light to see.
10. Discuss the most common cause of decreased visual function in the older adult.
a. Cataract
b. Glaucoma
c. Diabetic retinopathy
d. Age-related macular degeneration (AMD)
11. Explain the statement that normal visual acuity is 20/20.
a. The top number indicates the distance the person is standing from the chart.
b. The bottom number gives the distance at which the normal eye could have read it.
12. Describe the method of testing for presbyopia.
a. Hand held vision screening.
13. To test for accommodation, the person focuses on a distant object and then shifts the gaze
to a near object about 6 inches away. At near distance, you would expect the pupils to
________(dilate/constrict) and the axes of the eyes to _____________.
a. Constrict
b. Converge
14. Concerning malalignment of the eyes axes, contrast phoria with tropia.
a. Phoria: mild weakness when fusion is blocked.
b. Tropia: more severe, constant, malalignment,
15. Describe abnormal findings of tissue color that are possible on the conjunctiva and sclera,
and describe their significance.
a. General reddening, cyanosis of the lower lids, yellowing of the sclera.
1. Name the 6 sets of extraocular muscles and the cranial nerve that innervates each one.
a. Abducens nerve (CN VI) – abducts the eye
i. Lateral rectus muscle
b. Troclear nerve (CN IV) – enables to look downward and inward
i. Superior oblique muscles
c. Oculomotor nerve (CN III)
i. Superior rectus muscle
ii. Inferior rectus muscle
iii. Medial rectus muscle
iv. Inferior oblique muscle
2. Name and describe the 3 concentric coats of the eyeball.
a. Sclera (outer layer): tough protective, white covering.
b. Choroid (middle layer): dark pigmentation to prevent light from reflecting
internally. Heavily vascularized to deliver blood to the retina.
c. Retina (inner layer): visual receptive layer of the eye, light waves are changed
into nerve impulses.
3. Name the functions of the ciliary body, the pupil, and the iris.
a. Ciliary body: controls the thickness of the lens.
b. Iris: functions as a diaphragm, varying the opening at its center.
c. Pupil: reacts to amount of ambient light and accommodation, or focusing an
object on the retina.
4. Describe the anterior chamber, the posterior chamber, and the vitreous body.
a. Contains clear, watery aqueous humor produced by the ciliary body. The fluid
delivers nutrients to the surrounding tissues and drain metabolic wastes.
5. Describe how an image formed on the retina compares with its actual appearance in the
outside world.
a. The image formed on the retina is upside down and reversed from the actual
appearance.
6. Describe the lacrimal system.
a. Provides constant irrigation to keep the conjunctiva and cornea moist and
lubricated.
, 7. Define pupillary light reflex, fixation, and accommodation.
a. Pupillary light: normal constriction of the pupils when bright light shines on the
retina.
b. Fixation: a reflex direction of the eye toward an object attracting our attention.
c. Accommodation: the adaptation of the eye for near vision.
8. Concerning the pupillary light reflex, describe and contrast a direct light reflex with a
consensual light reflex.
a. Direct: constriction of the pupil.
b. Consensual: simultaneous constriction of the other pupil.
9. Identify common age-related changes in the eye.
a. Visual acuity diminishes after 50 yr./o.
b. Near vision is affected because of decreased power of accommodation after 40
yr./o and may have blurred vision and difficulty reading.
c. Requires more light to see.
10. Discuss the most common cause of decreased visual function in the older adult.
a. Cataract
b. Glaucoma
c. Diabetic retinopathy
d. Age-related macular degeneration (AMD)
11. Explain the statement that normal visual acuity is 20/20.
a. The top number indicates the distance the person is standing from the chart.
b. The bottom number gives the distance at which the normal eye could have read it.
12. Describe the method of testing for presbyopia.
a. Hand held vision screening.
13. To test for accommodation, the person focuses on a distant object and then shifts the gaze
to a near object about 6 inches away. At near distance, you would expect the pupils to
________(dilate/constrict) and the axes of the eyes to _____________.
a. Constrict
b. Converge
14. Concerning malalignment of the eyes axes, contrast phoria with tropia.
a. Phoria: mild weakness when fusion is blocked.
b. Tropia: more severe, constant, malalignment,
15. Describe abnormal findings of tissue color that are possible on the conjunctiva and sclera,
and describe their significance.
a. General reddening, cyanosis of the lower lids, yellowing of the sclera.
