Which Snellen result indicates decreased visual acuity compared with normal?

Which Snellen result indicates decreased visual acuity compared with normal?

• A. 20/20
• B. 20/30
• C. 20/40
• D. 20/15

Answer: (B)

Visual acuity is assessed with a Snellen chart, and normal vision is 20/20. When the denominator is larger than 20, acuity is decreased because you must be closer to read details that a person with normal vision can read from farther away. So, a result that means you can read at 20 feet what a person with normal vision can read at 30 feet shows decreased acuity. It indicates impairment relative to normal. A 20/20 result is normal, 20/15 is better than normal, and 20/40 indicates a more pronounced decrease than 20/30.

Visual acuity is assessed with a Snellen chart, and normal vision is 20/20. When the denominator is larger than 20, acuity is decreased because you must be closer to read details that a person with normal vision can read from farther away. So, a result that means you can read at 20 feet what a person with normal vision can read at 30 feet shows decreased acuity. It indicates impairment relative to normal. A 20/20 result is normal, 20/15 is better than normal, and 20/40 indicates a more pronounced decrease than 20/30.