Which of the following denotes normal vision?

Normal vision is denoted by a measurement of 20/20, which is the standard for visual acuity testing. This ratio indicates that a person can see at 20 feet what should normally be seen at that distance. In other words, if you have 20/20 vision, your visual capability is considered optimal, meaning you can clearly see objects that are 20 feet away.

Measurements such as 20/30, 20/50, and 20/100 indicate varying degrees of visual impairment. For example, a 20/30 measurement means that a person must be at 20 feet to see what a person with normal vision can see at 30 feet, suggesting a slight reduction in acuity. Similarly, 20/50 and 20/100 indicate a more significant decline in vision, with the latter indicating that a person can see at 20 feet what a person with normal vision sees at 100 feet. Therefore, the correct answer emphasizes that 20/20 is the benchmark for what is classified as normal vision.