What Does 2020 Vision Mean
When we are talking about eyesight, there are many fractions and terms that get tossed around after an eye exam. Not everyone may know what these actually mean! For instance, 20/20 vision has long been thought of to mean perfect vision. However, this is not actually true– 20/20 vision simply means that a person has normal eyesight, not that it is perfect. Read on to learn more about 20/20 vision, as well as vision acuity and how it is measured to inform us of the sharpness of a person’s eyesight.
What Is 20/20 Vision?
20/20 vision is used to describe the sharpness of a person’s vision. It, and other fractional values, are given after you take a visual acuity test. 20/20 vision refers to the amount of detail you can see in an object, as compared to someone with normal vision. Someone with 20/20 vision is able to see the same amount of detail from 20 feet away from an object that the average person with average eyesight would be able to see. Interestingly enough, 20/20 vision does not mean that you have perfect eyesight. This is a common misconception. Rather, 20/20 vision means that you have normal eyesight, and it is a benchmark value instead!
What If You Don’t Have 20/20 Vision?
As we mentioned above, many people mistakenly believe a 20/20 vision is the perfect vision. It does not. However, if you do not have 20/20 vision and your vision is impaired, it is not something to be too concerned about! The number of adults that actually have 20/20 vision is fairly low. There are only about 35% of adults with 20/20 vision. If you do not have 20/20 vision, this can be corrected with glasses or with contact lenses, though there may be some underlying issues that require eye surgery. This all depends on the person affected, since every case is different, and is something that you can discuss with your eye doctor after you receive your visual acuity test results.
What Is Visual Acuity?
Visual acuity, sometimes also referred to as acuity of vision, is a term that is used to measure the sharpness and quality of a person’s vision. It is commonly measured at 20 feet away from an eye chart or object so that you know how well you would be able to identify details at 20 feet away when compared to someone who has normal vision. Visual acuity is considered to be the most common clinical measurement of how a person’s eyes function. However, it is important to note that visual acuity does not give a comprehensive picture of how someone’s eyes or vision works. There are other qualities that are not measured with visual acuity and would need to be evaluated separately, such as sensitivity to colour, peripherals, depth perception, and more. However, visual acuity is still very important and is one of the first tests done by an optometrist!
How Is Visual Acuity Tested?
Now that you know what visual acuity means, you may wonder how it is actually tested. A visual acuity test is one that will determine how well you can describe details, such as a letter, a picture, or a symbol. These will be examined from various distances in order to measure your visual acuity. It is common for children to take regular visual acuity tests or eye exams so that their vision can be monitored as they develop. This is important because early detection of an eye issue can make it easier to take preventative measures and ensure that a person’s eyesight does not get worse!
Meanwhile, adults typically do not undergo visual acuity tests as regularly as children do. If you are an adult, you will likely only undergo an eye exam or visual acuity exam if you are experiencing an issue with your vision at that time. If you find that the clarity of your vision has changed, this is another reason that you may have a visual acuity test. Testing your eyesight for a driver’s license may also be required. There are two kinds of visual acuity tests, which we will go into greater detail about below. These are called the random E and Snellen tests.
Random E
The first of the two visual acuity tests that we will be going over is the random E test. This is a test that is usually used for either children or adults who sometimes struggle with identifying letters. During this test, you do not have to read out random letters– instead, the only letter you are dealing with is the capital letter E. When you begin to go down the eye chart, the position and the size of the capital letter E will change, facing in different directions and also decreasing in size. The eye doctor will ask you to identify which direction the E is facing. Is it facing left, right, up, or down? Once you are no longer able to see it clearly, the test will conclude. Both the random E test and the other test, the Snellen test, are calculated based on the line on which the most Es are able to be identified correctly.
Snellen
The other test that is commonly used to measure visual acuity is the Snellen test. This one uses an eye chart of mixed letters and symbols, unlike the random E test. The letters and symbols are organized into rows, which begin to get smaller as the chart goes on. You will be asked to stand 20 feet away from the eye chart and then cover one of your eyes. The eye doctor will then ask you to read letters or symbols aloud. Once you are no longer able to identify them, your eye doctor will ask you to repeat the process with your other eye.
Why Is Visual Acuity Important?
You know what visual acuity is, but it is also important that you understand the significance of visual acuity. Why is this important? Typically, a visual acuity test is the first thing that you will do when going through a comprehensive eye exam at the optometrist or eye doctor. This is because a visual acuity test is an easy way for you and your doctor to identify the signs of vision problems. If you are able to identify them, you will then be able to take precautions and preventative measures to be sure that these issues do not worsen.
Some of the issues that can be identified during a visual acuity test are refractive errors such as nearsightedness or farsightedness. Hyperopia, or farsightedness, is an issue that manifests when you have a sharp far-range vision and less clear close-range vision. On the other hand, myopia, which is another name for nearsightedness, is the inverse. It occurs when a person has clear close-range vision but has issues with their far-range vision. Usually, the issue would be that it is out of focus. Of course, there are other factors in your vision that would not be measured by a visual acuity test, such as depth perception and peripheral awareness, to name a few.
Understanding Visual Acuity Results
If you undergo a visual acuity test, you will receive your results as a number in fractional form. For instance, your results might be 20/20 or 20/40 for visual acuity. So, what does this mean? The top, or first number, is the distance that you stand away from the chart during the test– for example, 20 feet away from the chart, as is usual. Most cases will be a fraction that begins with 20. The second number or the bottom number of the fraction is the distance from which a person who has normal eyesight would be able to read the same line that you were able to read.
Generally, even when you miss a couple of letters or symbols on a line, this will still count toward your results. When you get your visual acuity results back, 20/20 is considered to be the normal vision. Another result, such as 20/30, means that you have slightly worse eyesight than normal– or someone who has 20/20 vision. This would mean that you can see details at 20 feet away that a person with normal vision would be able to see at 30 feet away.
Frequently Asked Questions
What does 20/30 vision mean?
If you have 20/30 vision, this generally means that your eyesight is worse than average. It means that when you are 20 feet away from a person or an object, you are able to see details that most others– those with a normal vision– can see at 30 feet away from the same object.
What does 20/70 vision mean?
A person who has 20/70 vision has much poorer eyesight than someone who is considered to have normal vision. If you have 20/70 vision, then you need to be 20 feet away from an object in order to see it with the same details that someone with normal vision can see when they are 70 feet away from the object. The ratio of 20/70, or other ratios, is used to describe visual acuity, which is also known as the sharpness of vision.
What does it mean having 2020 vision?
Most people who have heard the term 20/20 vision mistakenly believe this means someone has perfect vision. However, that is not necessarily true. As the ratio simply describes visual acuity, having 20/20 vision is a descriptor of how sharp the person’s vision is. This ratio of 20/20 does mean that a person has pretty good vision, though! Someone who has 20/20 vision will be able to see an object clearly from 20 feet away. Those who have normal vision can also see the same object and the same details from 20 feet away. For this reason, 20/20 vision refers to normal vision, rather than perfect vision.
What does it mean to have 20 40 vision?
Another ratio you may see in regards to eyesight is 20/40 vision. So, what does 20/40 vision mean? 20/40 vision means that you are able to see the amount of detail on an object from 20 feet away that a person with normal eyesight can see from 40 feet away. A person who has 20/40 vision is nearsighted, but not incredibly so– only slightly. They may not even need glasses or contact lenses, but of course, this should be discussed with their eye doctor in order to make the best choice.
What does it mean to have 20 10 vision?
20/10 vision is actually better than 20/20 vision. 20/20 vision is normal vision, not necessarily perfect vision, so there are people out there who can have better vision than 20/20 vision. Ratios like 20/10 or 20/15 can be better than someone with 20/20 vision. Having 20/10 vision means that you are able to see something and see details that are 20 feet away, but someone with normal vision can see these same details at 10 feet away, rather than 20 like you are able to. 20/10 vision is fairly rare, as less than 1 percent of people actually have it!
What does it mean to have 20 15 vision?
20/15 vision is another type of vision acuity that is actually better than 20/20 vision– which is considered to be normal eyesight. It means that you are able to see something that is 20 feet away that most people with normal vision would see at 15 feet away. You are able to see more details at more distance than someone with normal eyesight is able to see, essentially. Of course, vision that is actually better than 20/20 is rare and hard to come by, so there are not very many out there who do have 20/15 vision.
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About Dr. Steven Hoang
Dr. Steven Hoang, a licensed optometrist with over 10 years of experience, specializes in comprehensive eye care, including the diagnosis and management of conditions such as dry eye, corneal dystrophies, and other vision-related health issues. His extensive knowledge in ocular health, coupled with his patient-first approach, ensures that you receive the highest level of care. Dr. Hoang is committed to staying up-to-date with the latest advancements in eye care technology and treatment options. He is an active member of Alberta College of Optometrist. Learn more about Dr. Steven Hoang here and his professional background by visiting his LinkedIn profile.
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