eye movements

Question 1

emmetropia

Answer 1

normal spherical-shaped eye

Question 2

myopia

Answer 2

elongated eyeball

Question 3

hyperopia

Answer 3

flattened eyeball shape

Question 4

keratoconus

Answer 4

normal eye can have some spherical aberrations or imperfection significant
-becoming cone shaped

Question 5

astigmatism

Answer 5

a type of spherical aberration
-affects ability of the eye to focus
-cornea has various radii of curvature

Question 6

presbyopia

Answer 6

the decreasing in visions as you age

Question 7

diabetic retinopathy

Answer 7

loss of blood supply and nutrients within the eyes and will no longer work well

Question 8

cataract

Answer 8

when the cornea and lens looks thick and milky
-can be normal with aging

Question 9

glaucoma

Answer 9

increased pressure due to an increase of aqueous humor
-insufficient disposal

Question 10

scotoma

Answer 10

blind spot due to lesions within the retina area

Question 11

detached retina

Answer 11

retina sits on the sides and back and it could be damaged due to injury a genetics and can move off the globe and floats in the fluid
-layers can separate

Question 12

macular degeneration

Answer 12

age related eye disease affecting the small portion of vision for straight away vision called the macula

Question 13

why do we have conjugate eye movements?

Answer 13

for stable images in two eyes
-to avoid double vision

Question 14

smooth pursuit

Answer 14

eye tracking
-following a moving object

Question 15

saccades

Answer 15

directing the gaze from one target to another
-point A to point B

Question 16

VOR

Answer 16

reflexive movement of the eyes in response to vestibular stimulation
-usually produces conjugate eye movement in opposite direction of the head

Question 17

nystagmus

Answer 17

rhythmic oscillation of the eyes
-fast in one direction and slow in the other direction

Question 18

optokinetic nystagmus

Answer 18

fixating on passing objects
-eye tracks it until its out of view then the eye saccades back to forward position and fixates on a new object

Question 19

spontaneous nystagmus

Answer 19

when nystagmus occurs with no prompts for it to occur
-lesions to labyrinth, CN 8, brainstem or cerebellum

Question 20

vertigo

Answer 20

sense that the world is spinning or that your head/body is spinning

Question 21

two types of vertigo

Answer 21

objective - objects/world spinning
subjective - self spinning

Question 22

syncope

Answer 22

fainting

Question 23

what is the term for lightheaded

Answer 23

presyncope

Question 24

fixation to stop nystagmus

Answer 24

the visual fixation on a target
-can make it difficult to see if the patient’s nystagmus

Question 25

gaze

Answer 25

horizontal gaze and vertical gaze
-there are connections across the midline because eyes should gaze in the same direction

Question 26

hold signal

Answer 26

saccade signals need a hold signal if the eye is to remain in place following a saccadic movements
-if this does not occur, the eyes will drift back to center

Question 27

opthalmoplegia

Answer 27

disturbances or weaknesses of extraocular eye muscles
-nucluear, internuclear and supranuclues

Question 28

nuclear opthalmoplegia

Answer 28

due to lesions in the nuclei of ocular motion or associated cranial nerves
-CN 3, 4 and 6
-loss of movement with that certain muscle (i.e. lateral gaze due to CN 6 with the lateral rectus)

Question 29

internuclear opthalmoplegia

Answer 29

lesions involving the medial longitudinal fasciculus
-derangement of eye movements

Question 30

supranuclear opthalmoplegia

Answer 30

lesions involving the cerebral cortex
-reflexes intact, but voluntary saccades interrupted