If you want to become a pilot, one of the many requirements is to have “good vision.” However, what does that entail, exactly? How important is it to have 20/20 vision and what does that mean?
Over a long period, optometrists have studied what the average human being can see from 20 feet away. 20/20 vision means that you have the same vision as an average human being and you can see the same thing they might see standing 20 feet away from something. There are different labels for other kinds of vision as well, such as 20/200, the legal cutoff for blindness. It means that you have to stand 20 feet away from something, when someone with perfect vision can see 200 feet away. Some people actually have 20/10 vision, better than 20/20. Good news is that 20/20 is not necessary in the real world in that most road, signs, newspapers, magazine, and objects in the world we live are calibrated for 20/40 vision
Having good vision entails more than just having 20/20 vision. There are other components that prove that you have good vision: seeing details, reading for long periods without discomfort, processing what you read well and healthy eyes. If you have these, you have good vision and eye health.
Also known as, nearsightedness, myopia means that you can see things near to you but not far away. If you have severe myopia, far away things appear to be blurry and you could not be a pilot.
The opposite of myopia is hyperopia, or farsightedness. It is also the inverse, meaning that you can see far away things very well, but anything nearby is blurry. Hence, the term “reading glasses,” the glasses you only need to read small details in books, magazines, or computer monitors. photo credit: http://es.wikipedia.org/wiki/Test_de_Snellen