# What does 6/6 (20/20) vision mean?

> 6/6 vision means you can read at 6 metres what a person with normal sight is expected to read at 6 metres. It is the metric version of 20/20, which is the same measurement in feet. It describes how sharp your distance vision is. It is not a measure of overall eye health.

Source: https://seebetter.co.za/blog/what-does-6-6-vision-mean/
Publisher: See Better (https://seebetter.co.za/)
Section: Eye tests
Published: 2026-10-11
Last updated: 2026-10-11

## Key points

- 6/6 and 20/20 are the same result, one measured in metres and one in feet.
- The larger the second number, the weaker the vision: 6/12 is weaker than 6/6.
- Many people see better than 6/6 with or without glasses.
- You can have 6/6 vision and still have an eye condition or need reading glasses.

## How the two numbers work

The result comes from the letter chart used in an eye test, called a Snellen chart. It is written as a fraction:

- The **first number** is the distance at which you are tested. In South Africa that is 6 metres. In the United States it is 20 feet, which is almost exactly the same distance.
- The **second number** is the distance at which a person with normal sight could read the smallest line that you managed.

So 6/6 means that at 6 metres you read the line a normally sighted person reads at 6 metres. If your result is 6/12, the smallest line you could read at 6 metres is one that a person with normal sight could read from 12 metres away. In other words, you need to be twice as close to see the same detail.

## 6/6, 6/9, 6/12: how the results compare

| Metric | Feet | What it means |
| --- | --- | --- |
| 6/4.5 | 20/15 | Sharper than the standard. Common in healthy young adults. |
| 6/6 | 20/20 | The standard for normal distance vision. |
| 6/9 | 20/30 | Slightly below the standard. Many people do not notice. |
| 6/12 | 20/40 | The minimum for a light vehicle driving licence in South Africa. |
| 6/18 | 20/60 | Distant detail such as road signs is clearly blurred. |
| 6/60 | 20/200 | Only the largest letter on the chart can be read. |

Each eye is measured on its own, and then both together, with and without your glasses.

## Is 6/6 perfect vision?

No. It is the expected standard, not the upper limit. Plenty of people read one or two lines below the 6/6 line. More importantly, the chart only measures one thing: how sharp your central vision is at distance, in good light, with high-contrast black letters on a white background.

It does not tell you about:

- your near vision, which is why someone with 6/6 sight can still need reading glasses
- your side (peripheral) vision
- how well your eyes work together and judge depth
- colour vision
- how you see in poor light or against glare
- the health of the inside of your eyes

That last point matters most. Conditions such as [glaucoma](https://seebetter.co.za/blog/glaucoma-symptoms-and-testing/) and early diabetic eye disease can be present for years while you still read the 6/6 line comfortably. A good chart result is one part of an eye test, not the whole of it.

## What if my vision is worse than 6/6?

Most often it means you have a refractive error: you are [short-sighted, long-sighted](https://seebetter.co.za/blog/short-sighted-vs-long-sighted/) or have [astigmatism](https://seebetter.co.za/blog/what-is-astigmatism/). These are corrected with glasses or contact lenses, and for most people the right lenses bring vision back to 6/6 or better.

If lenses do not bring your sight up to the standard, your optometrist will look for the reason. It could be a cataract, a problem at the back of the eye, or an eye that never developed full vision in childhood, known as a [lazy eye](https://seebetter.co.za/blog/lazy-eye-amblyopia/).

## 6/6 vision and your prescription

People often mix these up. The chart result, such as 6/9, is how well you see. The prescription, such as -1.25, is the lens you need to see better. Two people with the same chart result can have different prescriptions. To make sense of the lens numbers, see [how to read your glasses prescription](https://seebetter.co.za/blog/how-to-read-your-glasses-prescription/).

## The driving standard in South Africa

To hold a licence for a car or motorcycle you need at least 6/12 in each eye, with or without glasses or contact lenses. If one eye is weaker than that, the other must be at least 6/9. Heavy vehicle and professional drivers need 6/9 in each eye. The full rules are in [the eye test for your driver's licence](https://seebetter.co.za/blog/drivers-licence-eye-test-south-africa/).

## Frequently asked questions

### Is 6/6 the same as 20/20?

Yes. They are the same measurement in different units. Six metres is roughly 20 feet, so countries that use metres write 6/6 and countries that use feet write 20/20.

### Can vision be better than 6/6?

Yes. A result of 6/5 or 6/4.5 is better than the standard, and it is common in young adults with healthy eyes, with or without glasses.

### Does 6/6 vision mean I do not need an eye test?

No. The chart measures sharpness only. Eye diseases such as glaucoma can develop while you still see 6/6, so regular eye tests remain important. Most adults should have one every two years.

### Is 6/9 vision bad?

Not really. It is slightly below the standard and is often easily corrected with glasses. You may notice that road signs and subtitles are a little soft, especially at night.

## About See Better

See Better is a mobile optometry practice in Gauteng, South Africa. A qualified, HPCSA-registered optometrist travels to the client's home, workplace, school or event, so there is no practice to visit.

- Areas served: Johannesburg, Pretoria (Tshwane), Ekurhuleni (East Rand), the West Rand and the Vaal.
- Eye test at home: R450 (cash price).
- Eye test + frame + single vision lenses + tint: R1199 (cash price).
- Eye test + frame + bifocal lenses + tint: R1699 (cash price).
- Eye test + frame + multifocal lenses + tint: R2099 (cash price).
- All glasses carry a 1-year warranty.
- We are registered with most medical aids and charge at medical aid tariffs.
- Book on WhatsApp: +27 66 181 8667 (https://wa.me/27661818667)
- Email: info@seebetter.co.za
- Website: https://seebetter.co.za/