Eyes

Question 1

name the 6 sets of extraocular muscles and the cranial nerve (CN) that innervates them

Answer 1

1. superior oblique (CN IV - trochlear)
2. medial rectus (CN III - oculomotor)
3. inferior rectus (CN VI - abducens)
4. inferior oblique (CN III - oculomotor)
5. lateral rectus (CN III - oculomotor)
6. superior rectus (CN III - oculomotor)

Question 2

name and describe the 3 coats of the eye

Answer 2

1. sclera = outer, fibrous
2. chorioid = middle, vascular
3. retina = inner, nervous

Question 3

name the functions of the ciliary body, pupil + iris

Answer 3

1. ciliary body = muscle for accommodation, release aqueous humour, controls thickness or iris, bulge to focus on near + flattens for far
2. pupil = hole that light passes through, constricts / dilates
3. iris = biconcave disc located anterior to pupil, refractory, helps focus

Question 4

describe how an image formed on the retina compares with an objects actual appearance in the outside word

Answer 4

image formed is upside down + reversed from its actual appearance in the outside world

Question 5

describe the lacrimal system

Answer 5

provides constant irrigation to keep the conjunctiva + cornea moist + lubricated

Question 6

define the papillary light reflex, fixation + accommodation

Answer 6

1. papillary light reflex = normal constriction of pupils when bright light shines on retina (no conscious control)
2. fixation = reflex direction of eye towards an object, attracting our attention
3. accommodation = adaption of eye near vision

Question 7

concerning the pupillary light reflex, describe and contrast a direct light reflex, with consensual light reflex

Answer 7

optic nerve (CN II) carries sensory afferent message + then synapses with both sides of the brain

Question 8

identify common age-related changes in the eye

Answer 8

• lacrimal gland involute (decrease tear production)
• infiltration of degenerative lipid material shows around limbus
• decrease pupil size
• lens loses elasticity, becomes hard + glass like

Question 9

discuss the most common of decreased visual function in older adults

Answer 9

cataract formation, glaucoma, age-related macular degeneration, diabetic retinopathy

Question 10

explain the statement of normal visual acuity (20/20)

Answer 10

numerator = distance at which patient can read the letters
denominator = distance at which a normal person can read the letters

Question 11

describe the method of testing for presbyopia

Answer 11

hand help vision screening

Question 12

to test for accommodation, the person focuses on a distant object, then shifts the gaze to a near object about 15cm away. At a near distance, you would expect the pupils to ____ and the axes of the eyes to ____

Answer 12

constrict
converge

Question 13

concerning malalignment of the eye axes, contrast phobia with tropia

Answer 13

phoria = mild weakness when fusion is blocked
tropia = more severe constant malalignment

Question 14

describe abnormal findings of tissue color that are possible on the conjunctiva and sclera and their significance

Answer 14

general reddening, cyanosis of lower lids, yellowing of sclera

Question 15

describe pingueculae VS pterygium

Answer 15

pingueculae = yellowish patch / bump on conjunctiva that results in deposit of protein, fat and/or can often lead to a pterygium
pterygium = triangular growth on sclera

Question 16

describe conjunctivitis

Answer 16

infection of conjunctivitis
aka pink eye

Question 17

describe subconjunctival hemorrhage

Answer 17

small blood vessel in the white of the eye breaks

Question 18

describe iritis

Answer 18

inflammation of iris + anterior chamber

Question 19

describe acute glaucoma

Answer 19

iris blocks drainage angle of eye causing increase in pressure