Joel Temperly on Instagram: "A Snellen test is a common eye exam used to measure visual acuity, meaning how clearly a person can see at a distance. It’s the test where you’re asked to read letters from a chart on the wall, usually starting with big letters at the top and moving down to smaller ones. The chart is called a Snellen chart, and it’s typically placed about 20 feet (6 meters) away from the person being tested. Each line of letters corresponds to a level of vision. Your result is writte