What statement is true regarding the Snellen chart?

The correct statement regarding the Snellen chart is that the normal eye can distinguish two points separated by an angle of 1 minute of arc. This ability is fundamental to visual acuity measurement.

In more detail, the Snellen chart is designed to determine how well a person can see by testing their ability to resolve details at a specific distance. The concept of visual acuity is based on the smallest angle of separation that the eye can distinguish, which is typically measured in minutes of arc. A normal visual acuity of 20/20 corresponds to the eye’s ability to resolve detail down to 1 minute of arc. This means that at a distance of 20 feet, the individual can see letters that subtend an angle of 5 arc minutes at the eye – equivalent to distinguishing two points that are 1 minute apart.

Although options suggesting larger angles such as 2, 5, or 10 minutes of arc reflect reduced visual acuity, they do not align with the standard for what is considered normal vision. Normal vision is defined by the threshold of 1 minute of arc, making this the fundamental criterion for visual acuity measurements with tools like the Snellen chart.