Visual Acuity Testing Flashcards

What is 'amblyopia' as it relates to visual acuity testing?

Answer: Reduced VA in one eye not correctable with lenses due to abnormal visual development

Amblyopia ('lazy eye') is reduced best-corrected VA in one eye caused by abnormal visual development in childhood, not explainable by organic disease alone.

When using a mirror system to simulate 20 feet in a small room, the actual room distance is typically:

Answer: 10 feet

A plane mirror placed 10 feet from the patient doubles the apparent distance to 20 feet, allowing standard VA testing in smaller rooms.

When asking a patient to read the Snellen chart, the paraoptometric should instruct the patient to:

Answer: Read the smallest line they can see clearly

Patients should be directed to read the smallest line they can see clearly, as this identifies their actual acuity threshold.

Which abbreviation correctly documents visual acuity tested without glasses?

Answer: sc

The abbreviation 'sc' (sine correctione) means without correction and is used to document uncorrected visual acuity.

A Snellen fraction of 20/15 indicates the patient:

Answer: Sees better than average at distance

20/15 means the patient sees at 20 feet what a normal person must be at 15 feet to see, indicating above-average distance visual acuity.

Which step should the paraoptometric take if a patient wears bifocals during near visual acuity testing?

Answer: Ensure the patient looks through the reading (bifocal) segment

For near VA testing with bifocals, the patient should look through the bifocal (lower) segment to ensure the reading correction is being evaluated.

LogMAR visual acuity charts (such as the ETDRS) are preferred in research because they:

Answer: Provide equal spacing of optotypes and consistent letter count per line

ETDRS/LogMAR charts have equal numbers of letters per line and equal spacing between lines on a logarithmic scale, allowing more precise statistical analysis.