Visual Acuity Testing Flashcards

When testing visual acuity monocularly, which eye is typically tested first?

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).

What does it mean if a patient's best-corrected visual acuity (BCVA) is 20/20?

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.

Legal blindness in the United States is defined as best-corrected visual acuity of:

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.

When recording that a patient read the 20/30 line but missed 2 letters, how should this be documented?

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.

Illumination of the Snellen chart should be maintained at approximately:

Answer: 85–100 foot-candles

Standard chart illumination should be approximately 85–100 foot-candles to ensure consistent, reliable visual acuity measurements.

Which notation represents the metric equivalent of 20/20 vision?

Answer: 6/6

In the metric system, 6/6 is equivalent to 20/20 because 6 meters is the metric equivalent of 20 feet.

If a patient reads 2 extra letters on the line below the 20/40 line, VA should be recorded as:

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.