When people hear “20/20 vision,” they automatically think “perfect vision” or vision so good that they could be a pilot.
Unfortunately, that isn’t necessarily true.
Having 20/20 vision doesn’t mean your eyesight is perfect, nor does it necessarily reflect the overall health of your eyes. It only measures how clearly you can see at a distance of 20 feet, and doesn’t account for other important aspects of vision, such as color perception, depth perception, peripheral vision, eye coordination, or overall eye health.
At Insight Optometry, we believe clear answers matter just as much as clear vision. While having 20/20 vision is a benchmark, it is only through comprehensive eye exams that you can fully gauge true visual health.
What Does 20/20 Vision Actually Mean?
20/20 vision refers to normal visual clarity. It describes how clearly you can see from 20 feet away compared to the average person. If you have 20/20 vision, you can see details that are 20 feet away that most people with normal vision can see at that same distance. The measurement of how clear and sharp your vision is at a standard distance is called visual acuity.
The 20-foot distance is used because it’s far enough to test distance vision without changing eye focus. It offers a standardized way to keep eye results consistent.
It is estimated that only 30-35% of people naturally have 20/20 vision or better. Yes, you can have better vision than 20/20 (we will get to that in just a bit). The rest of us have to get to the 20/20 mark by using corrections like glasses, contact lenses, or laser surgery.
It is also important to note that this vision test only measures distance clarity and sharpness. It does not measure many other aspects of your eye.
How the Eye Chart Works: Understanding the Snellen Chart
We have all likely seen the Snellen Chart. It is the one with rows of letters that get smaller as you go down.
The Snellen Chart is the most common form of eye chart and is often used during routine eye exams, when applying for a motor vehicle exam, or at school screenings. The snellen chart is used during the visual acuity test.
During a visual acuity test, individuals are asked to identify letters on a chart. The goal is to determine the smallest line of letters they can read clearly.
If your visual acuity measures 20/40, your distance vision is not as sharp as someone with 20/20 vision. Specifically, 20/40 vision means what you can just make out clearly at 20 feet, someone with 20/20 vision can still see it clearly if it is 40 feet away.
On the other hand, someone with 20/15 vision has sharper distance vision than someone with 20/20 vision. A person with 20/15 vision can see a letter clearly from 20 feet away, while someone with 20/20 vision would need to be 15 feet away to see it with the same clarity. Some people can even have 20/10 vision naturally, though this is not common.
To put into perspective, in Canada, legal blindness is defined as visual acuity that is 20/200 or worse WITH correction. This definition comes from the Canadian National Institute for the Blind, and is used to determine eligibility for certain services, benefits, and support for people with significant vision loss.
Why 20/20 Vision Isn’t “Perfect”?
Having perfect vision is a lot more than scoring a 20/20 score or better on a visual acuity test.
While someone may have normal or better than average distance clarity and sharpness, other aspects of “perfect vision” include depth perception, peripheral vision, normal colour vision, and low-light or night vision. And importantly, overall eye health.
A comprehensive eye exam will provide a thorough eye health assessment to establish if someone truly has “perfect” vision.
Why You May Not Have 20/20 Vision?
The most common reason people don’t have 20/20 vision is a refractive error, which means that light doesn’t focus properly inside the eye. Nearsightedness, or myopia, makes distant objects appear blurry, while farsightedness, or hyperopia, can make close-up objects blurry. Astigmatism, can make vision look stretched or shadowy.
The good news is that refractive errors often can be corrected by prescription glasses and contact lenses- allowing you to achieve the benchmark 20/20 score or at least get close to it.
Remember, wearing prescription eyeglasses doesn’t mean your eyes are unhealthy. It just means they need the right support to see clearly.
Eye Health Conditions That 20/20 Alone Cannot Detect
Visual acuity tests are basic measurements of how clearly you can see at a distance, and as we’ve discussed, they don’t capture everything about your eye health. For example, if you have an eye disease that isn’t affecting your vision yet, a visual acuity test won’t detect it. Conditions such as glaucoma, macular degeneration, or early diabetic retinopathy can develop without reducing visual clarity, meaning a person can still have 20/20 vision even while the disease is present.
At Insight Optometry, we use the latest eye technology and instruments like the iCare Tonometry, Optos Optomap Digital Retinal Imaging, Zeiss Cirrus OCT (Optical Coherence Tomography), and the Humphrey Visual Field Analyzer 3 to check every aspect of your eye.
Why Regular Comprehensive Eye Exams Still Matter?
Comprehensive eye exams are essential for early detection of eye diseases and for a complete eye health assessment.
These exams look at all aspects of your eye, including visual acuity, eye coordination and focus, eye pressure, and retinal and optic nerve health.
Booking comprehensive eye exams every two years is recommended, and in some cases yearly exam may be recommended by your doctor, especially for older adults, and individuals with diabetes and other health concerns, including high blood pressure (hypertension), high cholesterol, autoimmune diseases, neurological conditions (like MS) and various cancers.
Comprehensive eye exams can reveal signs of retinopathy, optic nerve swelling, or vessel blockages long before vision deterioration symptoms appear, helping to prevent serious vision loss or even systemic health crises like strokes.
Comprehensive Eye Care Solutions in Halifax, NS
At Insight Optometry, our team uses the latest technology to provide you with the absolute best health care solutions.
Whether you are a returning client or a new one, we take the time to explain results, answer questions, and provide the best advice for your eye care needs.
We also pride ourselves on offering a range of eye care solutions all under one roof. Our services include:
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Glasses and contact lens fittings, including specialty contact lenses
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Dry eye assessment and care
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Neurolens for eye strain and headaches
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Laser vision correction counselling and co-management.
Book an online appointment or call (902) 422-4444 in case of emergencies. You can also visit our eye clinic located at Cambridge Suites Plaza, 1575 Brunswick St., Halifax, NS, B3J 2G1.
FAQs
1: Is 20/20 vision the same as perfect vision?
No. Having 20/20 vision simply means you have normal distance clarity, not perfect overall eyesight.
2: If my vision is 20/20, do I still need eye exams?
Yes. Eye health issues can exist even when vision is clear.
3: What does it mean if one eye is 20/20 and the other isn’t?
Each eye can have light focus on it differently, so it is common to need a different amount of correction for each eye.
4: Can wearing glasses make my eyes weaker?
No, wearing glasses doesn’t make your eyes weaker. They just make it easier for you to see clearly.
5: What vision do I need to drive in Nova Scotia?
For a standard licence, corrected vision of at least 20/40 in the better eye is required.
6: When should I ask about laser vision correction?
If you are not a fan of wearing glasses or contact lenses, you can opt for laser vision correction. Our optometrists can guide you on availability and suitability.
