Position the patient 20 feet in front of the Snellen eye chart (or hold a Rosenbaum pocket card at a 14 inch "reading" distance).
Have the patient cover one eye at a time with a card.
Ask the patient to read progressively smaller letters until they can go no further.
Record the smallest line the patient read successfully (20/20, 20/30, etc.)
Repeat with the other eye.
MCC Paramedics are held to a higher standard.