2

Question 1

KNOW PERCENTAGES!

• for ages 45+: what percent experience vision impairment? Severe VA impairment?
• for ages 65+: what percent experience vision impairment? Severe VA impairment?

Answer 1

45+: impairment = 17%, severe = 9%

65+ impairment = 21%, severe = 11%

Question 2

MEMORIZE!!!
What is the height of a 20/20 letter at 20 feet on a STANDARD SNELLEN chart?

-How tall is a 20/20 letter at 1 meter?

1M = 20/___?

Answer 2

8. 77mm
9. 45mm tall @ 1m

1M = 20/50

Question 3

Snellen notation - what’s the numerator? denominator? (think alphabetical!)
-Q: you move the snellen chart to 5ft and the pt reads the 80 size letter; what’s the snellen VA? What was the most important factor needed to solve this?

Answer 3

distance/letter size (D over L)

5/80 = 20/X - X =320

Question 4

What two steps do you take if you need to reduce any near card to M notation?

Answer 4

1) measure the letter height in mm

2) Divide by standard 1.45mm! OR multiply by .7

Question 5

Functional visual impairment - _____

3 things that must exist to qualify for being impaired?**

Answer 5

limitation d/t disease or congenital condition unable to be corrected w/ refraction, surgery or meds

1) 20/200 or worse in BETTER eye
2) 20 deg in WIDEST meridian (or worse), OR HOMO HEMI
3) CS worse than 1.7 log CS BINOCULARLY

Question 6

Contrast is super important. What are two key things contrast sensitivity will help determine w/ your LV pts?

Answer 6

1) ability to use optical devices, 2) dominant eye (will pick eye w/ higher contrast over eye w/ better VA)
- other: amt. of mag required, lighting, longitudinal parameter, overall function
- decreases in “vision” are often not d/t vision - they’re d/t changes in contrast

Question 7

pts w/ reduced contrast may automatically need to use a LVD such as a ____

-what does CS testing w/ eye DOMINANCE help you to determine?

Answer 7

CCTV: if CS is already