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20/40 Vision: Understanding Your Visual Acuity

So, you went to the optometrist for your annual eye exam, she busted out the eye chart, and you thought, “Easy!” You could rattle off letters with no problem ... until you got to that last line of letters. Suddenly, things looked a little blurry. Then the eye doctor told you that you have 20/40 vision. But what does that mean? Did you just fail your eye test?

While 20/40 vision might not be the perfect score you were hoping for, you definitely didn’t fail. But, it does mean that you have a slight case of myopia or nearsightedness — meaning you need to get closer to an item before you can see it clearly, or your near vision is better than your far vision.

We’ll walk you through what these numbers mean, what it’s like to live with 20/40 vision, and what you can do to correct your eyesight and achieve clear vision.

What Do the Numbers in 20/40 Vision Mean?

20/40 vision: A male eye doctor pointing to a vision test chart with rows of letters on it.

Whether you have 20/20 vision or 20/40 vision, the numbers represent your visual acuity — or how accurately you see objects from a specific distance. In a standard visual acuity test, that distance is 20 feet, which makes up the top number in your visual acuity measurement.

The Top Number

When your doctor conducts your vision test, they’ll have you sit or stand 20 feet away from a Snellen Chart (that’s the official name for the thing on the wall with all the letters). The first number in your visual acuity measurement, 20, represents that 20 foot distance — your distance from the eye chart when your eye exam was performed.

In the U.S., the top number is always 20 because it’s thebenchmark for an optometry exam. But if you get your vision tested overseas, where they use the metric system, the standard distance for an eye exam will be 6 meters. So, in Canada or Australia, a person with 20/20 vision will have 6/6 vision. And a person with 20/40 vision will have 6/12 vision.

The Bottom Number

Now, onto that bottom number, which represents your distance vision compared to the “average person” or “normal person.” Your eye test is comparing how much you can see from a 20-foot distance to how much a normal person can see from a 20-foot distance.

If you have 20/20 vision, then you can see the same amount from 20 feet away as a normal person can see. But only about 35% of the population has 20/20 vision, so it’s actually more normal not to be normal.

If you have 20/40 vision, then you need to be 20 feet away to see what a normal person can see from 40 feet away. (i.e., they can stand twice as far away as you and still see everything that you can see. That sounds like an unfair advantage to us!)

Some people think that 20/20 vision is “perfect vision,” but that’s not true. It’s more accurate to call it “normal vision.” Some people have visual acuity scores that are even better than 20/20 — these people might have scores of 20/15 or 20/10. If you have 20/10 vision, then you can see things from 20 feet away that people with normal vision can only see from 10 feet away. It’s like you have super vision!

On the other end of the scale, people with really low vision have visual acuity scores that can’t be corrected to 20/20 — even with the thickest pair of eyeglasses. Some people with low vision will have 20/40 visual acuity with their glasses on. People whose vision can only be corrected to 20/200 with glasses meet the standard for legal blindness.

Is 20/40 Vision Bad?

You might be starting to panic if you think you have 20/40 vision, especially if you’ve had 20/20 vision for most of your life. We’re here to tell you that, no, it’s not “bad” to have 20/40 vision.

To give you some perspective, eye doctors can only correct your vision to around 20/70, and when someone is considered legally blind, they can only correct their vision to 20/200. So 20/40 vision is really not that bad!

What’s It Like to Have 20/40 Vision?

A pair of hands making a rectangle shape to frame a sunset in a field.

If you’ve been living with 20/40 vision for a while, it may feel normal and you may not need corrective lenses. (Although many people find having a pair of glasses makes life easier even if they don’t use them all the time.)

Doctors will always recommend corrective lenses for patients whose visual acuity is worse than 20/40. (We’re talking scores of 20/45 and beyond.) 20/40 is that borderline score where glasses will probably improve your day-to-day life, but you’re not legally required to have them.

In the majority of states, you can pass your driver’s license exam and legally drive without glasses if you have 20/40 vision. But, it’ll take you longer to read road signs than it would take a driver with 20/20 vision. Wearing glasses while you drive will help you read those signs sooner so you never miss an exit again.

Here are a few other ways that corrective lenses can improve your daily life if you have 20/40 vision:

  • You’ll be able to see the chalkboard menu at your favorite cafe, even when you’re at the back of the line.

  • You can sit further from the whiteboard or projector screen in classes or work meetings.

  • You’ll see details like the subtleties of leaves on a tree better.

  • You’ll be able to read subtitles at the movies.

  • You’ll see more when you look out at a sweeping vista after a long hike or during a day at the beach.

  • You’ll notice more stars in the sky at night.

When you’re used to having 20/40 vision, the experience of having 20/20 vision is a beautiful thing. And if you’re worried about the look of corrective lenses, don’t be. People who wear glasses are often perceived as more honest, trustworthy, and intelligent. Plus, there are plenty of fun styles that will help you express your unique personality.

How to Improve Your Vision

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If you have 20/40 vision and are longing for 20/20, there are steps you can take to improve your vision. Step one: Call your favorite optometry practice and schedule a comprehensive eye exam.

Get Your Eyes Checked Every Year

Step one: Call your favorite optometry practice and schedule a comprehensive eye exam.

Regular eye exams are your first line of defense when it comes to your eye health. Your doctor will check for common vision problems, like nearsightedness (myopia), farsightedness (hyperopia), presbyopia, and astigmatism, and then prescribe corrective lenses, like single-vision or progressive lenses. They’ll also examine your retina health and check your eye pressure, and rule out serious impairments like cataracts, glaucoma, and macular degeneration.

Make Small Lifestyle Changes

In addition to eye exams, there are a few other ways you can take care of your eye health. First, it’s really important to address dry eyes if you suffer from them. Using warm compresses, staying hydrated, placing a humidifier in your bedroom, and diligently wearing sunglasses are all great ways to help keep your eyes happy and healthy.

Another must when taking care of your eyes is eating an eye-healthy diet. A diet tailor-made to give your eyes a boost will be full of fruits, vegetables, whole grains, and omega-rich fish.

Generally speaking, you want your diet to be low in fat and rich in produce and whole grains to maintain eye health. This diet is also great for your heart — your eyes rely on tiny arteries to bring them nutrients and oxygen, just like your heart relies on large arteries to do the same.

One of the easiest ways to care for your eyes is to take a daily fish oil supplement. Fish oil comes in capsules and is full of long-chain omega-3 fatty acids, which can help with the symptoms of dry eyes, age-related macular degeneration, and a lower risk of glaucoma.

Cut Out the Main Culprits

Just like there are things that are good for your eyes, there’s also some stuff you should definitely cut out. One of the main culprits here is smoking. Smoking can cause puffiness around your eyes, lead to vision loss, and can cause eye conditions like macular degeneration and cataracts.

It’s also a good idea to cut down on screen time. When you stare at a screen for long periods of time, you blink a lot less. As you might imagine, this can dry your eyes out over time and cause discomfort.

But, even with proper eye care, you shouldn’t expect to wake up one day and suddenly have 20/20 vision without corrective lenses. If you have 20/40 vision, start by trying out a pair of glasses.

Options like Lasik eye surgery and contact lenses can exacerbate dry eye, and for 20/40 vision, you won’t need the ‘round-the-clock vision correction that contact lenses provide. Eyeglasses allow you to enhance your vision when you need it (like when you’re at the back of the line at that cafe), and keep your eyes working on their own the rest of the time.

A great pair of glasses is all you need to correct your 20/40 vision!

Can You Correct Your Vision To Be 20/10?

Now that you know that some people have even better vision than 20/20, you might be wondering if you can get in on the action and request glasses with 20/10 support.

Although it’s technically possible to make glasses this strong, eye doctors usually shy away from it. When you wear glasses with correction this intense, you risk worsening your short-sighted vision and making it harder to see things up close.

Even With 20/40 Vision, You’ve Got an Eye for Style

20/40 vision: A diverse group of smiling young people wearing glasses from Pair Eyewear.

If you have 20/40 vision, then you need to be 20 feet away from something that people with normal vision can see from 40 feet away. That means people with 20/20 vision can see things from twice as far away as you can. Not. Fair. Even the playing field by getting a personalized pair of eyewear!

Sure, you don’t legally need glasses if you have 20/40 vision. (You can drive without them in most states.) But, life is better when you can see clearly. Plus, glasses are a fun accessory — and we never miss a chance to accessorize!

At Pair Eyewear, you can get your eyeglasses for as little as $60. Then, add stylish Top Frames that clip over the top of your Base Frames to completely change your look. Add a little sparkle, get ready for a special occasion, or have fun in the sun — without buying a second pair of frames. There’s never been a clearer choice!