Term
| T/F VAs are a measurement of "vision" |
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Definition
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Term
| Dr. London talks about four different types of Visual Acuity. What are they? |
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Definition
1. Minimum Detectable
2. Minimum Discriminable Offset
3. Visual Resolution
4. Visual Recognition |
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Term
Match each test with the appropriate one of the four types of Visual Acuity.
1. Fixation Disparity
2. Broken Wheel
3. Preferential Looking
4. HOTV chart
5. Candy Bead
6. Interferometry
7. Vernier Offset
8. Kirschen Dot |
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Definition
1. Minimum Discriminable Offset
2. Visual Recognition
3. Visual Resolution
4. Visual Recognition
5. Minimum Detectable
6. Visual Resolution
7. Minimum Discriminable Offset
8. Minimum Detectable |
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Term
| Minimum Detectable Acuity will (over- / under-)estimate Snellen Acuity. |
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Definition
Overestimate.
It's more of a contrast task than a Snellen one, so your score is going to be waaaaay higher if you're just detecting the presence of a black dot on white. |
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Term
| Out of the 4 types of acuity, which ones will underestimate Snellen and which ones will overestimate Snellen? |
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Definition
One (Visual Recognition) is Snellen.
All of the other three will overestimate Snellen acuity. |
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Term
What is the limit of…
1. Minimum Detectable
2. Minimum Discriminable Offset
3. Visual Resolution
4. Visual Recognition |
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Definition
1. 1 arcsec (speck)
2. 2 - 10 arcsec (offset gap)
3. 30 arcsec (grating)
4. 60 arcsec (Snellen) |
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Term
| Recognition acuity is __ times inferior to being able to identify the minimum detectable… |
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Definition
| 60x inferior (to seeing a speck) |
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Term
| What are the most ideal clinical forms of acuity measurement? |
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Definition
Resolution and Recognition
(Recognition, in particular, is closest to how we function in real life.) |
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Term
| If we were to filter our acuity tests into three categories, what might those categories be? |
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Definition
Basic (requires minimal patient response, eg. preferenial looking, OKN, 10pd BD test)
Medium (our standard VA tests, eg. Lea, HOTV, Bailey Cereal Test)
Advanced (specific tests for amblyopia, eg. psychometric acuity, Bailey-Lovie Chart) |
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Term
| What's the problem with OKN drums? |
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Definition
| Our reflex can practically run itself independent of a developed visual cortex, so a sort of 'blind sight' situation can exist for infants and amblyopes. |
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