CPOA Visual Acuity Testing 3 — Questions and Answers
Question 1: When testing visual acuity monocularly, which eye is typically tested first?
- Left eye always
- Right eye always (Correct answer)
- The eye with better vision
- The eye with worse vision
Correct answer: Right eye always
By convention, the right eye (OD) is tested first, followed by the left eye (OS), and then both eyes together (OU).
Question 2: What does it mean if a patient's best-corrected visual acuity (BCVA) is 20/20?
- The patient needs no glasses
- With the best possible correction, the patient sees normally (Correct answer)
- The patient has perfect color vision
- The patient's prescription is correct
Correct answer: With the best possible correction, the patient sees normally
BCVA of 20/20 indicates that with optimal correction, the patient's visual acuity is normal, regardless of what their uncorrected VA may be.
Question 3: Legal blindness in the United States is defined as best-corrected visual acuity of:
- 20/100 or worse
- 20/200 or worse (Correct answer)
- 20/400 or worse
- Count fingers or worse
Correct answer: 20/200 or worse
In the US, legal blindness is defined as best-corrected VA of 20/200 or worse in the better eye, or a visual field of 20 degrees or less.
Question 4: When recording that a patient read the 20/30 line but missed 2 letters, how should this be documented?
- 20/30-2 (Correct answer)
- 20/30+2
- 20/40
- 20/25
Correct answer: 20/30-2
Missed letters are noted with a minus sign after the VA fraction; 20/30-2 means the patient read the 20/30 line but missed 2 letters.
Question 5: Illumination of the Snellen chart should be maintained at approximately:
- 50–100 lux
- 85–100 foot-candles (Correct answer)
- 10 foot-candles
- 200–300 lux only
Correct answer: 85–100 foot-candles
Standard chart illumination should be approximately 85–100 foot-candles to ensure consistent, reliable visual acuity measurements.
Question 6: Which notation represents the metric equivalent of 20/20 vision?
- 6/20
- 6/6 (Correct answer)
- 4/4
- 1.0/1.0
Correct answer: 6/6
In the metric system, 6/6 is equivalent to 20/20 because 6 meters is the metric equivalent of 20 feet.
Question 7: If a patient reads 2 extra letters on the line below the 20/40 line, VA should be recorded as:
- 20/40-2
- 20/40+2 (Correct answer)
- 20/30
- 20/35
Correct answer: 20/40+2
Extra letters read on the next smaller line are recorded with a plus sign; 20/40+2 means the patient read the 20/40 line and 2 letters on the next line.
CPOA Visual Acuity Testing 3
When testing visual acuity monocularly, which eye is typically tested first?