Exam 4 -- Complete and Randomized Flashcards
1
Q
What are the five indications for an EOG?
A
Retinitis Pigmentosa Siderosis Bulbi Vitelliform Dystrophy (Best Disease) Fundus Favimaculatis (Stargardt Disease) Chloroquine (Plaquenil) Retinopathy
2
Q
Between apperceptive and associative agnosia, which is more severe?
A
Apperceptive.
3
Q
________ stereo cells make up 20% of disparity detectors
A
Tuned inhibitory (fine)
4
Q
Fine stereo cells are sensitive to specific disparities, up to what point?
A
Up to 1 degree.
5
Q
When tested at 16 cpd, a 70 year old patient will require how much more contrast than a 20 year old patient?
A
Three times more contrast
6
Q
What is the resting potential of the front of the eye?
A
About 6 mV
7
Q
________ stereo cells make up 50% of disparity detectors
A
Tuned excitatory (fine)
8
Q
Blindsight is when a patient is blind but can accurately point to the location of a visual stimulus or report the direction of motion. What is the classic explanation for the location of damage that causes blindsight? Where does the damage more likely occur?
A
Classic explanation is superior colliculus; reality is probably damage to V1 that leaves spared “islands”.
9
Q
With an optic nerve disease such as glaucoma, would a focal PERG give a normal or abnormal result?
A
Abnormal
10
Q
The Inferior Temporal area (IT) is also known as?
A
V4
11
Q
With a macular lesion, would a standard ERG give a normal or abnormal result?
A
Normal
12
Q
Hemispatial neglect is usually caused by a lesion in which area of the brain, on which side?
A
Inferior parietal lobe, right side (so left visual field affected).
13
Q
What is Usher syndrome?
A
RP + deafness
14
Q
Complex cortical cells respond to what kind of stimulus?
A
Unidirectional movement.
15
Q
Damage to which area is thought to cause apperceptive agnosia?
A
Right parietal lobe.
16
Q
Which of the extra striate cortices is the end of the parvocellular stream?
A
V4
17
Q
Comparing a standard scotopic ERG to a normal photopic ERG, which is faster?
A
Photopic is faster
18
Q
List each of the stops that information from magno cells in the LGN passes through on its way to V5/MT.
A
- Layer 4C-alpha in V1
- Layer 4B in V1
- Thick dark stripes in V2
- V5/MT
19
Q
In amblyopia, would a focal PERG give a normal or abnormal result?
A
Normal
20
Q
What are the three clinical applications of an ERG?
A
Assessing the patency of the retina and choroid, locating the site of damage, and separating damage to rods vs cones
21
Q
_______________ is a reduction in pereceived object size and can lead to teleopsia.
A
Micropsia
22
Q
Projections to the extrastriate area originate in particular from which layers of V1?
A
Layers 2/3
23
Q
Comparing a standard scotopic ERG to a normal photopic ERG, which is slower?
A
Scotopic is slower
24
Q
True or false: simple and complex cortical cells are sensitive to the length of a stimulus (they have end stops).
A
True.
25
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would VEP show a normal result?
Only hysteria/malingering would show a normal result.
26
What age range is considered the critical period of visual development, during which time amblyopia can develop?
6 months to 2 years.
27
What are the three types of amblyopia? Which is most severe? Which is least severe?
Deprivational, strabismic, and refractive. Deprivational is most severe, refractive is least severe.
28
The percentage of people with stereoacuity thresholds equal or better than 85 arcseconds decreases with age. According to the study cited in the presentation, what percentage of older people had full (20 arcsec) stereopsis, and what percentage had no stereopsis?
27% had full stereopsis, 29% had no stereopsis
29
In order to "tease out" a VEP wave from background noise, you have to know when to look for it. This coresponds to the amount of time between the light being flashed to the signal arriving at the striate cortex, which is how long?
80 ms
30
The antidepressant trazodone can cause which visual hallucinations?
Palinopsia and polyopia
31
Which is more common, congenital prosopagnosia or acquired prosopagnosia?
Congenital.
32
What is the average refractive error at age 2.5 months?
+2.50
33
There is a regular shift in orientation sensitivity as you move along the surface of the cortex. A complete circular set of orientation edge detectors is called what?
Hypercolumn
34
Suppose you are testing a nonverbal patient and would like to know whether the Rx you've found improves their VA. You run a VEP without the Rx, then again with the Rx. How do you expect the amplitude of the VEP to change if the Rx does indeed improve VA?
Amplitude should increase (increases with sharper retinal image).
35
In retinitis pigmentosa, would a standard ERG give a normal or abnormal result?
Abnormal
36
The Middle Temporal are (MT) is also known as?
V5
37
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would EOG show a normal result?
All would be normal except retinitis pigmentosa.
38
With an optic nerve disease such as glaucoma, would a standard ERG give a normal or abnormal result?
Normal
39
True or false: a macular hole would affect a standard flicker ERG.
False; the standard ERG tests the whole retina. You'd have to use a focal flicker ERG in order to see the effect of a specific area of the retina.
40
What are the five stages of Best Disease?
1. Previtelliform
2. Vitelliform
3. Pseudohypopyon
4. Vitelliruptive
5. Atrophic
41
On a transient VEP, you expect to see three positive deflections and three positive deflections. Which of the positive deflections is the largest? Which of the negative deflections is the largest?
Positive #2 is the largest; negative #3 is the largest
42
Base out makes the binocular image look _______ (smaller/larger).
Smaller
43
_______________ is an enlargement of objects seen and can lead to pelopsia.
Macropsia
44
With an optic nerve disease such as glaucoma, would an EOG give a normal or abnormal result?
Normal
45
What is the average refractive error at age 3 years?
+1.00
46
In retinitis pigmentosa, would an EOG give a normal or abnormal result?
Abnormal
47
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would standard ERG show an abnormal result?
Only retinitis pigmentosa would show as abnormal.
48
What cell type is thought to cause the c-wave on an ERG?
RPE cells
49
What is the average refractive error at age 1 year?
+1.50
50
The Arden Ratio for a patient with ocular albinism is above what value?
300%
51
What kind of scotoma is often found in a patient with RP?
Ring scotoma
52
What is the average refractive error at age 6 months?
+1.75
53
How long does a light rise take to reach its peak on an EOG?
10-15 minutes.
54
In which layer of V1 does figure-ground and binocularity begin?
Layer 2
55
If you wanted to test the entire retina function, you would use a __________ ERG. If you wanted to test a specific area, you would use a __________ ERG.
Entire retina: full-field. Specific area: focal.
56
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would EOG show an abnormal result?
Only retinitis pigmentosa would show as abnormal.
57
A full-field (standard, flash) ERG is derived primarily from the ___________ (inner/outer) retina.
Outer.
58
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would focal PERG show a normal result?
Only hysteria/malingering and amblyopia would show a normal result.
59
At what age is contrast sensitivity up to adult-like levels?
9 years
60
What is the name of the phenomenon where a visual immage recurrently appears after the stimulus has disappeared?
Palinopsia
61
True or false: with optic neuritis, VEP latency will increase or decrease as the patient undergoes remissions and exacerbations.
False; once the latency increases, it stays increased.
62
With hysteria or malingering, would an EOG give a normal or abnormal result?
Normal
63
What are the light sensitive components of the EOG?
Photoreceptors
64
In amblyopia, would a VEP give a normal or abnormal result?
Abnormal
65
Which layer of V1 sends fibers to the superior colliculus?
Layer 5
66
Suppose you did a pattern ERG three times: once stimulating the fovea and the periphery, once stimulating just the fovea, and once stimulating just the periphery. When would the amplitude of the PERG be relatively high, and when would it be relatively low?
The amplitude of a PERG is relative to the area of the retina stimulated, so the amplitude would be high when stimulating both the fovea and periphery. Stimulating only the fovea but not the periphery (and vice versa) would have a decreased amplitude.
67
The magnocellular layers in the LGN synapse with which layer of V1?
4C-alpha
68
A standard (flash, full-field) ERG shows positive and negative deflections. Which wave, a or b, has a negative deflection? Which cell type causes it?
A-wave has a negative deflection and is caused by the photoreceptors.
69
How could a patient be blind but have a normal VEP?
If the damage causing blindness is located downstream of V1, VEP would be normal (since it focuses between the optic nerve head and V1).
70
A standard (flash, full-field) ERG shows positive and negative deflections. Which wave, a or b, has a positive deflection? Which cell types causes it?
B-wave has a positive deflection and is caused by the Mueller and/or bipolar cells.
71
True or false: a formed hallucination is a sensory perception in the absence of an external stimulus.
True. This is what distinguishes it from visual illusions, which are misperceptions of a visual stimulus.
72
With an optic nerve disease such as glaucoma, would a VEP give a normal or abnormal result?
Abnormal (though it may be normal early on in the disease)
73
The parvocellular layers in the LGN synapse with which layer of V1?
4C-beta (also 4A)
74
The Arden Ratio is the light rise divided by the dark trough. What are normal values?
180% to 250%
75
Hallucinations caused by which condition often cause inanimate objects to be viewed as living beings or parts of living beings?
Parkinson disease.
76
Forced preferential looking is a way to measure a child's acuity using grating patterns. What percent of correct performance indicates the level of the child's VA?
75%
77
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would standard ERG show a normal result?
All would be normal except retinitis pigmentosa.
78
The percentage of people failing the D-15 test increases with age, primarily due to what kind of defects?
Tritan defects
79
What would the cortical dominance histogram look like for a patient with alternating exotropia?
It would be skewed toward 1 and 7, with little to no input to the other columns (since there is never concurrent input by both eyes)
80
During the vitelliform stage of Best Disease, the lesions has an egg-yolk appearance and are usually centered on the macula and can be multifocal. How bad is VA in this stage?
VA is usually in the 20/20 to 20/40 range.
81
Simple cortical cells respond to what kind of stimulus?
Orientation. They can be on-off, or edge detectors.
82
_______________ is the transfer of visual images from one half of the visual field to the other.
Visual allesthesia.
83
What is the name of the condition in which blind patients experience vivid, complex visual hallucinations?
Charles Bonnet Syndrome
84
Plaquenil is used for autoimmune diseases like lupus. What is the name of the sign that can be seen on OCT of a patient with Plaquenil retinopathy?
Flying saucer sign
85
True or false: ERG on a patient with Leber Congenital Amaurosis would be a flat line.
True.
86
There are two categories of coarse stereo cells: far and near. Which of these is excited if an object is beyond the point of fixation and inhibited if the object is closer than the point of fixation?
Far coarse cells. Near coarse cells are the opposite (excited to nearer than fixation, inhibited to further than fixation).
87
Moderate and higher uncorrected astigmatism during childhood causes what kind of amblyopia? How would you treat it?
Meridional amblyopia; treat with full-time wear of full correction of all cylinder measured on wet retinoscopy.
88
Which cells in the visual cortex have axons that usually do not leave the cortex?
Stellate
89
Cortical blindness is the loss of vision in V1 despite intact eyes, optic nerves, and optic radiations. What is the name of the condition if patients are unaware of their blindness? What are some causes of cortical blindness?
Anton Syndrome. Cortical blindness can be caused by birth defects, trauma, Creutzfeld-Jakob Disease, and epilepsy meds.
90
True or false: hypercomplex cells are real.
False; they are not real. They were proposed by Hubel and Wiesel, but turned out to be incorrect.
91
___________ stereo cells make up 30% of disparity detectors.
Coarse
92
Focal epileptic hallucinations are most often caused by seizures in what area?
Posterior temporal-parietal junction. Focal epileptic seizures can also cause nystagmus, macropsia, and kinetopsia.
93
If you want to know if the fovea is working, which part of the VEP do you care more about: the amplitude or the latency?
Amplitude.
94
Kollner's Rule recap: conditions in the inner retina and pathways cause what type of color vision anomaly? What conditions fall into these categories?
Inner retina/pathway cause red-green defects.
Inner retina: Leber's optic atrophy (aka Leber's Hereditary Optic Neuropathy) and toxic amblyopia (aka toxic optic neuropathy).
Pathway: various lesions
95
Development of contrast sensitivity, vernier acuity, and grating acuity takes place beginning around what age?
Over 32 months
96
What is the average refractive error at age 4 years?
+1.25
97
Comparing a standard scotopic ERG to a normal photopic ERG, which is smaller?
Photopic is smaller
98
Steady-state VEP is a type of flicker VEP, in that the resulting graph shows a sine wave (in normal patients). What is the most common frequency of the phase-reversing checkerboard pattern used?
20 Hz
99
VEP can be used to objectively estimate both a patient's VA and their contrast sensitivity by taking a series of measurements while changing the stimulus. In order to find the estimated VA or CS, you would then extrapolate from the line created by these measurements to what value?
Zero
100
Development of stereopsis, scotopic sensitivity, photopic/scotopic luminosity, and CFF takes place around what age?
2 months to around 6 months
101
Ocular dominance columns respresent neurons that get the majority of their input from _________ (one/both) eye(s).
One.
102
How much anisometropia is typically required for symptomatic aniseikonia?
2.00 D or more
103
In retinitis pigmentosa, would a VEP give a normal or abnormal result?
Abnormal (though it may be normal early on in the disease)
104
What is the average monocular VA at age 2.5 months?
20/280
105
True or false: concious attention enhances a multifocal VEP.
True.
106
True or false: the limits of contrast sensitivity before age 1 year is due to immaturities in the cortex.
False; the limitation is due to immaturities in the retina, not the cortex.
107
Which of the extra striate cortices is the end of the magnocellular stream?
V5
108
What percent in size difference is needed before aniseikonia causes symptoms? To what percent is the Aniseikonia Inspector Software accurate?
2% size difference needed for symptoms; Aniseikonia Inspector accurate to 0.1%
109
Damage to which area of the brain can result in akinetopsia?
V5
110
Dark adaptation in older individuals takes longer than in younger people. This is affected by senile miosis. How much does pupil size shrink per decade of life?
0.5 mm
111
Name some of the causes of Balint Syndrome.
CJD, perinatal hypoxia, nitroglycerin, Alzheimer's disease
112
Projections to the lower visual centers (LGN, pulvinar) original in particular from which layer of V1?
Layer 6
113
True or false: the diameter of the visual field changes little with age, but decreases dramatically with age with split attention.
True.
114
In which stage of Best Disease does the yellow material break through the RPE and accumulate in the subretinal space? What condition may this appear like?
Pseudohypopyon; may appear like central serous choroidopathy
115
In amblyopia, would an EOG give a normal or abnormal result?
Normal
116
What is the name of the syndrome if a patient has RP and deafness?
Usher Syndrome
117
What percent of the retinal area is the fovea, and what percent of the striate cortex is devoted to foveal vision?
0.01% of retinal area; 8% of striate cotex.
118
With hysteria or malingering, would a VEP give a normal or abnormal result?
Normal
119
List each of the stops that information from parvo cells in the LGN passes through on its way to V4/IT.
1. Layer 4C-beta in V1
2. Blobs (for color), interblobs for detail (in V1)
3. Blobs to thin dark stripes in V2; interblobs to pale stripes in V2
4. V4/IT
120
It is thought that dementia-induced hallucinations and caffeine-induced hallucinations occur because of ________________.
Poor perfusion
121
_______________ is the perception that objects are farther away than they really are, and can result fro micropsia.
Teleopsia
122
How long does a dark trough take to reach its minimum on an EOG?
8 minutes
123
What is the human peak of contrast sensitivity, both in cpd and Snellen equivalent? By what age is this peak present?
Peak is 4 cpd (20/150 Snellen). This peak is present by age 4 years.
124
Micropsia and teleopsia are caused by defects in which part of the brain? (Hint: it's the same location as neglect and allesthesia.)
Parietal lobe
125
If you were to run both a photopic flicker ERG and a scotopic flicker ERG on an RP patient, which would have the more obvious deficit?
Scotopic.
126
What changes happen to the VEP of a person with an optic neuropathy, compared to normal? Which optic neuropathy is the one we tend to think about most?
The latency increases. Glaucoma is the optic neuropathy we tend to think about.
127
The Medial Superior Temporal area (MST) is also known as?
V3
128
What is the name of the phenomenon where structured geometric figures occur, often in a repetitive pattern?
Photopsia
129
What VF testing would you order for a patient on Plaquenil?
A 10-2 central VF
130
Dominance slabs and edge detectors are found in which areas?
V1 and V2
131
True or false: older patients have reduced CFFs, particularly at intermediate and high spatial frequencies.
True.
132
The koniocellular layers in the LGN synapse with which layers of V1?
Layers 2 and 3
133
What is the name of the condition that can occur with a metallic foreign body, causing the eyes to turn a rusty color and the pupil to dilate?
Siderosis Bulbi
134
True or false: even though the macula is normal looking (or near normal) in previtelliform stage of Best Disease, the EOG is still abnormal.
True.
135
Damage to which area is thought to cause associative agnosia?
Left temporal-occipital junction.
136
Which type of ERG is used for inner retina and ganglion cell function, PERG or mfERG?
PERG
137
What is the amplitude of the background "brain noise" when you're doing a VEP?
60 microvolts
138
True or false: VEP overestimates the VA for infants, compared to the values found with forced-preferential looking.
True.
139
Changes in a series of pictures are harder to see when they are presented side-by-side, but are easier to see when presented sequentially. Which retinal cell helps to spot the changes with sequential viewing?
Amacrine.
140
Adult vitelliform macular dystrophy resembles Best Disease, but can be distinguished by its later age of onset, smaller lesion size, and what other feature?
Normal EOG finding.
141
The early receptor potential (ERP) is a small portion of the ERG wave that is not seen clinically, since it requires a very bright light. What part of the retina causes the ERP?
Primarily the cones.
142
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would focal PERG show an abnormal result?
All would be abnormal except hysteria/malingering and amblyopia.
143
What is the average refractive error at age 2 years?
+1.25
144
What is the average monocular VA at age 6 months?
20/110
145
How would deprivational amblyopia affect the ocular dominance histogram?
The histogram would be skewed toward the eye without the deprivation (i.e., if a patient had a left congenital cataract, measuring the ocular dominance of the right striate would show skewing toward ipsilateral (7), while measuring the ocular dominance of the left striate would show skewing toward contralateral (1)).
146
Base in makes the binocular image look _______ (smaller/larger).
Larger
147
Comparing a standard scotopic ERG to a normal photopic ERG, which is bigger?
Scotopic is bigger
148
Which of the extra striate cortices is for color and facial/object recognition?
V4
149
In amblyopia, would a standard ERG give a normal or abnormal result?
Normal
150
_______________ is the perception that objects are closer than they really are, and can result from macropsia.
Pelopsia
151
What is the average monocular VA at age 4 years?
20/20
152
True or false: a cortically-blind infant can have an optokinetic nystagmus.
True. The OKN is controlled by the cerebellum and the pretectum, not the cortex.
153
What is the average monocular VA at age 3 years?
20/30
154
Which of the extra striate cortices is for binocular vision?
V2
155
What is the name of the phenomenon where a person sees the same object multiple times (at the same time)?
Polyopia
156
True or false: damage that causes prosopagnosia is usually bilateral, but is occasionally to the right hemisphere only.
True.
157
Where are the disparity cells of our visual system located?
V2 for complex cells, V3 for local motion.
158
What would cause an erroneously high Arden Ratio?
If the patient can't see the end points.
159
Which of the extra striate cortices is for local motion (like pursuits)?
V3
160
In which stage of Best Disease does the lesion become like a scrambled egg in appearance? How bad can VA get in this stage?
Vitelliruptive; VA no worse than 20/100
161
Which of the extra striate cortices is for global motion (like saccades)?
V5
162
Which type of ERG is used for outer retina (photoreceptors and bipolar) function, PERG or mfERG?
mfERG
163
A shortage of inhibition due to which neurotransmitter might underlie age-related visual deficits?
GABA
164
What is the amplitude of a typical VEP?
5 microvolts
165
Kollner's Rule recap: conditions in the media or in the outer retina cause what type of color vision anomaly? What conditions fall into these categories?
Media/outer retina cause blue-yellow defects.
Media: nuclear sclerosis.
Outer retina: ARMD and diabetic retinopathy
166
Which cells in the visual cortex have axons that commonly leave the cortex?
Pyramidal
167
A flicker ERG uses a 30 Hz light and looks like a sine-wave. Which type of retinopathy might cause the amplitude to decrease during the ERG?
Outer retina disease like diabetic retinopathy.
168
In retinitis pigmentosa, would a focal PERG give a normal or abnormal result?
Abnormal
169
With a macular lesion, would an EOG give a normal or abnormal result?
Normal
170
How many categories of ocular dominance are there? Which category consists of ipsilateral-only input (in a binocularly normal patient)? Which consists of contralateral-only input?
7 categories. 7 is ipsilateral, 1 is contralateral.
171
With a macular lesion, would a focal PERG give a normal or abnormal result?
Abnormal
172
Which optic neuropathy is often tested for with PERG?
Glaucoma.
173
True or false: in a VEP on a patient with ocular albinism, the amplitude would be decreased and the latency would be decreased.
False; the latency would be normal since the myelination has not been affected. Amplitude would be decreased since the patient has abnormal crossing at the optic chiasm, which decreases their VA (somehow…)
174
With hysteria or malingering, would a standard ERG give a normal or abnormal result?
Normal
175
What are the light insensitive components of the EOG?
RPE, cornea, lens, etc, but not the photoreceptors. These establish the dark trough.
176
What is the average monocular VA at age 1 month?
20/640
177
True or false: the voltage of the eye is greater in the light than it is in the dark.
True.
178
What kind of inheritance pattern does Leber's Congenital Optic Neuropathy exhibit? What kind of visual field defect might a patient with this condition exhibit?
Mitochondrial (mother to child). VF defect might be cecocentral.
179
Best Disease is inherited in what fashion?
Autosomal dominant
180
Reduction to the inferior longitudinal fasciculus has been associated with what type of agnosia?
Prosopagnosia.
181
What would cause an erroneously low Arden Ratio?
If the patient closes their eyes or looks away.
182
True or false: in the dark, the front of the eye is more negatively charged than the back of the eye?
False; the front of the eye is more positive than the back of the eye.
183
What is the average monocular VA at age 1 year?
20/90
184
In the final stage of Best Disease, atrophic, the small macular scar that remains can cause VA to drop below what level?
20/200
185
Binocular summation in a normal patient would cause an increase in the patient's VEP when testing binocularly, compared to monocular VEP. By what factor does VEP increase? Patients with what condition will deviate from this pattern?
1.4 (square root of how many eyes we have). Amblyopes will not have an increase of 1.4 in the amplitude of their dominant eye VEP to their binocular VEP.
186
What part of the retina is often affected first in a patient with RP? Which visual field?
Inferior retina, superior visual field.
187
Macular lesion, retinitis pigmentosa, optic nerve disease (such as glaucoma), amblyopia, and hysteria/malingering. For which of these conditions would VEP show an abnormal result?
All would be abnormal except hysteria/malingering. (Note: retinitis pigmentosa and glaucoma may have normal VEP early in the disease)
188
Suppose you did a VEP three times: once stimulating the fovea and the periphery, once stimulating just the fovea, and once stimulating just the periphery. When would the amplitude of the PERG be relatively high, and when would it be relatively low?
The amplitude of a VEP is relative to the amount of fovea stimulated, since a large part of the striate cortex is devoted to foveal vision. So stimulating fovea and periphery would have a high amplitude, but so would stimulating just the fovea. Stimulating just the periphery would have a very low amplitude.
189
What is the average monocular VA at age 2 years?
20/60
190
With a macular lesion, would a VEP give a normal or abnormal result?
Abnormal
191
Macropsia and pelopsia might be caused by defects in which part of the brain? (Hint: it's the same location as associative agnosia.)
Temporal-occipital junction
192
True or false: R/G color vision development starts around age 2 and may continue until adolescence.
True.
193
With hysteria or malingering, would a focal PERG give a normal or abnormal result?
Normal
194
Balint Syndrome is a triad of findings. What three findings are they?
Simultagnosia, oculomotor ataxia, and oculomotor apraxia.
195
List the average refractive errors for the following ages:
```
2.5 months
6 months
1 year
2 years
3 years
4 years
```
```
2.5 months: +2.50
6 months: +1.75
1 year: +1.50
2 years: +1.25
3 years: +1.00
4 years: +1.25
```
196
List the average visual acuities for the following ages:
```
1 month
2.5 months
6 months
1 year
2 years
3 years
4 years
```
```
1 month: 20/640
2.5 months: 20/280
6 months: 20/110
1 year: 20/90
2 years: 20/60
3 years: 20/30
4 years: 20/20
```
