What Does 20/20 Vision Mean?

If you have an eye exam and are told you have 20/20 (or 6/6) vision, does this mean you have perfect eyesight? What does that ACTUALLY mean? Is it possible to achieve even better than 20/20 vision? And what defines “perfect vision” anyway? To answer these questions, let’s take a closer look at the term ‘Visual Acuity’ to fully understand how ophthalmologists and optometrists measure the quality of your vision.

Visual Acuity

The term 20/20 is a measure of visual acuity; i.e. the sharpness of your vision. With the help of a standardised Snellen eye chart, ophthalmologists and optometrists can assess your visual acuity by measuring your ability to identify letters or numbers on the standardised eye chart from a specific viewing distance.

20/20 vision is the US terminology, also known as 6/6 vision here in NZ, for the standard of visual acuity that the majority of people can expect to achieve or even surpass following Laser Eye Surgery. The top number refers to the distance at which the chart is viewed – 20 feet (or 6 metres) – and the bottom number refers to the distance at which a person with ideal vision can see a letter clearly. Therefore if you have 20/40 (or 6/12) vision, this means that you will just be able to see the Snellen chart letter or number from a distance of 20 feet that a person with perfect eyesight will be able to see from 40 feet.

Vision Assessment Is Only Part Of The Equation

Although 20/20 vision means “normal’ vision, it does not necessarily mean you have perfect vision. The Snellen chart is a tool that simply indicates the sharpness or clarity of vision at a distance measured in standardised conditions, and thus it cannot predict the health of your eyes and the quality of your vision in all other conditions and situations. Other important vision skills include peripheral vision, eye coordination, depth perception, focusing ability, colour vision, how well you can see moving objects and objects that are similar in brightness to their background, which cannot be measured with the Snellen chart assessment.

Is it Possible To Have Better Than 20/20 Vision?

Yes, it’s indeed possible to have sharper than 20/20 vision. A common misconception is that 20/20 (6/6) acuity is “perfect”.  However, this is merely the baseline which is considered “normal” or “average”.
In actual fact, most people under the age of 25 with young, healthy eyes are capable of identifying at least some of the letters on the 20/15 line or even smaller letters on the Snellen chart.

Laser Eye Surgery

Most patients that come to us would love to ditch their glasses and contact lenses and achieve 20/20 vision. That’s why many New Zealanders suffering from vision difficulties, chose Auckland Eye for our state of the art technology and leading-edge laser eye procedures that can allow them to achieve radically improved vision, and depending on their original prescription, sometimes can achieve even better than 20/20 vision! As revolutionary as that sounds (and is!), we have already achieved fantastic results for our patients’ vision for more than two decades and we look forward to improving the lives of many more to come.

If you would like to book a consultation with us or find out more about how you can benefit from laser eye surgery, give us a call on 0800 63 93 93 or email laser@aucklandeye.co.nz