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20-20 vision
What is 20-20 vision?
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By looking at lots of people, eye doctors have decided what a "normal" human being should be able to see when standing 20 feet away from an eye chart. If you have 20/20 vision, it means that when you stand 20 feet away from the chart you can see what the "normal" human being can see. (In metric, the standard is 6 metres and it's called 6/6 vision). In other words, if you have 20/20 vision your vision is "normal" -- a majority of people in the population can see what you see at 20 feet.
If you have 20/40 vision, it means that when you stand 20 feet away from the chart you can see what a normal human can see when standing 40 feet from the chart. That is, if there is a normal person standing 40 feet away from the chart and you are standing only 20 feet away from it, you and the normal person can see the same detail.
You can also have vision that is better than the norm. A person with 20/10 vision can see at 20 feet what a normal person can see when standing 10 feet away from the chart.
Hawks, owls and other birds of prey have much more acute vision than humans. A hawk has a much smaller eye than a human being but has lots of sensors (cones) packed into that space. This gives a hawk vision that is eight times more acute than a human's. A hawk might have 20/2 vision!
20/20 Vision makes grassroots activism easy for busy people. We give citizens the information and tools they need to get involved on important issues like reducing air pollution from cars and power plants, keeping dangerous pesticides out of our food, limiting nuclear arms and making our country more secure. Our alerts tell you how to contact politicians and corporate officials and quickly and easily tell them you�re watching them on an urgent issue.Best of all, we engage activists through creative online and offline strategies and make it fun! 20/20 Vision promotes democracy by involving the public at critical decision points.
Check out www.2020vision.org for more info.
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