According to Optometry Australia’s 2020 Vision Index, 26 per cent of Australians have never visited an optometrist for an eye examination because they believe their vision is perfect. But what is ‘perfect’ vision?
Many Aussies are familiar with the phrase 20/20 vision and some consider it to mean the best vision can be, but do you know what it really means and is 20/20 vision perfect? Could it be possible to have better than 20/20 vision?
Let’s find out.
What do we mean when we say 20/20 vision?
20/20 vision is a phrase used to describe the clarity or sharpness (also known as acuity) of a person’s vision at 20 feet from a vision chart. 20/20 vision means the individual can see what the average person can see at 20 feet. In Australia as we use the metric system which is recorded as 6/6 instead of 20/20, as 20 feet equates to six meters.
Can you have better than 20/20 vision?
If 20/20 vision is measured against what the average person can see at 20 feet, it is indeed possible to have better than 20/20 vision.
For example, if a person has 20/15 vision it means they can see at 20 feet what the average person needs to be closer at 15 feet to see. In other words, people with 20/15 vision have sharper and clearer vision in comparison to people with 20/20 vision. This is not uncommon, particularly amongst children. The maximum acuity of the human eye without aids (e.g. binoculars) is thought to be around 20/10. Some birds, such as hawks, are believed to have an acuity of around 20/2, which is much better than human eyesight.
To add to this, while acuity is the standard test for the quality of sight, it’s important to take into consideration other aspects of vision such as peripheral vision, depth and colour perception, and focusing ability. All of these factors combined contribute to the strength of sight.
Therefore, although two people may both have 20/20 vision, due to other factors, one could have better vision than the other.
How do I find out if I have 20/20 vision?
You can find out if you have 20/20 vision by visiting your local optometrist for an acuity test. This is typically part of a battery of tests including health checks that comprise a comprehensive eye examination.
Please use our Find an Optometrist search function to find your local optometrist.
How will my optometrist test my visual acuity?
Many adults will be familiar with the visual acuity test when going for their driver’s licence or some may have taken the test when seeking employment.
For those who haven’t, an optometrist will have the patient sit 20 feet away from a wall-mounted vision chart, much like the one below. The patient will then cover one eye at a time and attempt to read all the letters on the chart as instructed by the optometrist.
If all the letters can be read successfully down to the 20/20 line the patient has 20/20 vision.