What does 20/20 vision mean?


Share this post:

If you wear glasses, contact lenses or ever had your eyes tested (which we hope that you have at least once…every 2 years), you have probably heard of the term 20/20 vision. But most people think that 20/20 vision is a superpower that only a few can possess. Quite frankly, it’s not. Most of us use the term loosely without digging that little bit deeper to find out what having 20/20 vision actually means.

So, what is 20/20 vision?


This term indicates that an individual has a visual acuity of 20/20.

It’s a term only used in North America. These figures are based on letter charts which are used in the standard sight test, such as the Snellen chart. The Snellen fraction derives from Herman Snellan, a Dutch Ophthalmologist who developed this format of measurement in 1862.

However, contrary to popular beliefs, it is possible to see better than 20/20 vision. A few individuals are able to see 20/15 vision and sometimes even smaller letters such as the 20/10 line of letters on the Snellen chart.

So, a case could be made that “normal” visual acuity today is an ability to identify letters that are a bit smaller than those on the 20/20 line of a traditional Snellen eye chart. However, a lot of factors must be considered when testing your vision and a chart through the internet wouldn’t be the wisest choice. A few of the factors contributing to how far down the chart you can clearly see could include but not confined to age, eye health, any eye diseases past or present, foods that you eat, or even down to whether you smoke or not [as smoking is known to contribute to overall bad eye health].

On the other hand, people are living longer today than they did in Snellen’s era. Identifying cataracts, which is considered a normal aging change in the eyes, could justify considering somewhat larger letters than those on the 20/20 line as being symptomatic of “normal” vision among adults in their 60s or older.


So, what is “perfect vision”?

Well, you are considered an extremely lucky individual to be able to see at all however, perfection is what society and humanity are drawn to possessing. So, the real question you have to ask yourself is “perfect vision for what?”.

You may be happy with 20/20 vision acuity that allows you to drive down the road on a sunny day and not miss a turn however, a friend may be happier without 20/20 vision but a pair of sunglasses that are anti-reflective, block glare and enhance contrast and quality of saturation. Depending on what you perceive to be the correct vision for you and your lifestyle, you will have to take into account other factors such as sharpness, how your eye reflects light and how your eyes react to objects moving quickly.

How can I find out whether I have 20/20 vision?

At Speccies, we are passionate about catering to individuals and discovering the needs of their eye health so feel free to give us a call today on 0844 884 4606 for an independent consultation.

Share this post: