Over ten million people in the United States have some form of vision problem, from simple nearsightedness to legal blindness. The majority of people will have vision problems in their lifetime, whether they were born with poor sight or it was a gradual progression with age. It’s not surprising; for such a small organ, the eye has many parts and a large responsibility, allowing for many areas in which something could go wrong. Consider how often cameras break or need to be replaced; eye health is critical in this regard as the possibility for error is so high and even the smallest problems can have a huge impact on eyesight.
Most people don’t have critical vision impairment, although there are roughly 1.3 million Americans who are considered legally blind. Some of the most common vision problems are caused by refractive errors within the eye and include amblyopia, myopia, hyperopia, presbyopia, and astigmatism.
20/20 vision is considered normal human vision. In essence, this means that our eyes can see an object twenty feet away as if the object truly is twenty feet away. If someone has 20/30 vision, they can see objects twenty feet away as though they are thirty feet away, meaning their vision is weaker than the average human. 20/10 vision, on the other hand, indicates that an individual can see something twenty feet away as though it is only ten feet away, designating above average vision. Most people who have vision significantly worse than 20/20 wear glasses or corrective lenses.
20/20 vision does not indicate perfect vision, however. Things like depth perception, peripheral vision, and the ability to differentiate colors all are included in what is considered perfect vision.
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