Can people have 40/40 vision? And if so, what would it be like?

Answer 1

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 meters 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. (From here on, please assume that the word normal has quotes around it.)

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. 20/100 means that when you stand 20 feet from the chart you can see what a normal person standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United States.

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.

So, if you had 40/40 vision, you would be seeing at 40 feet what a normal person would be seeing at 40 feet. So, it would be the same as 20/20.

Answer 2

You measure the vision in each eye, so a person would have 20/40 in each eye, not 40/40.

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 meters 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. (From here on, please assume that the word normal has quotes around it.)

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. 20/100 means that when you stand 20 feet from the chart you can see what a normal person standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United States.

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.

Answer 3

40/40 would be the same as 20/20
20/20 means that a normally sighted person sees at 20' what everyone sees at 20'
Same would be true for 40/40

Answer 4

20/20 is where you see things that are 20 ft away 20ft away. compare that to 40/40

Answer 5

20/20 and 40/40 is not the same thing 20/20 is the ability to read an eye chart from simply 20 feet away where as 40/40 is the ability to read an eyes chart with extreme magnification and extreme demagnification of the object with still having clear focus on the object.

Answer 6

things might be somewhat blurry and you
may need specks for reading or driving