What is 20 40 Vision?

20/40 vision means that when a person stands twenty feet from the vision chart, they can read what a normal individual can read at a distance of forty feet from the chart. Normal vision is 20/20, which means they can read the chart clearly at twenty feet. Better than normal vision would be 20/10, which means that a person can read the chart from twenty feet, where a normal person could read it from 10 feet.You can find more information here: