Final answer:
The Snellen chart test is the most commonly used method to measure visual acuity, involving lines of letters that decrease in size to establish sharpness of vision at a standard distance. Option B
Step-by-step explanation:
The most frequently used test for measuring visual acuity is the Snellen chart test. The Snellen chart presents a limited number of Roman letters in lines of decreasing size, which helps to assess the clarity and sharpness of the individual's vision at a fixed distance, usually 20 feet.
During this test, a person is asked to read the smallest line of letters they can from the chart. If a person can only read the big letters at the 20-foot line, then their vision is expressed as a ratio, with the second number representing the distance at which a person with normal acuity can read the same line (e.g., 20/60). option b