![]() Your colour vision is also not measured on the standard letter chart, and it helps you distinguish many objects on a day to day basis. Other muscles of the eye are now allowing you to scan from word to word across the line, and then the highly detailed action of jumping from one line, down to the next. As you are reading this article, those muscles are working hard to keep the type in focus. These muscles also enable our eyes to change focus from distant to near objects. ![]() These muscles are hugely beneficial to help us judge depths, speed and the fine movements required to scan lines of reading material. The muscles of our eyes coordinate our eye movement and the focusing of our eyes. ![]() How well our eyes are coordinated is also important. This ability to detect movement is what helps protect us from dangerous objects that might be hurtling toward us, especially in busy environments like crossing streets. Peripheral vision is really good at detecting movement rather than fine details. Without good peripheral vision you might walk into low tables, chairs, find yourself missing steps or accidentally standing on pets. This is your ability to see out the sides of your eyes, it helps you place yourself in space. Peripheral vision is very important, and it can’t be measured on a letter chart. Vision is far more complex than just being able to see black letters on a white chart! Peripheral vision Other aspects of our vision have a huge impact on how we see and navigate our day to day life. But it really only determines how good your vision is in a very static way. Using the letter chart is one way, and the simplest way of assessing a person’s quality of vision. Well on a day to day basis it may not be as important as we think it is. Just like America is one of the only nations still using Fahrenheit rather than degrees Celsius to record temperature.Ī standard Snellen vision testing chart with measurements from 6 meters and 20 feet. 20/20 and 6/6 represent the same sized letters, they just use different measuring systems to document the results.Īmerica hasn’t switched to the metric system, so it still uses charts based on feet, rather than on meters. So instead of the chart being 20 feet away, the chart is 6 metres away. In most other nations, like New Zealand and Australia, we use the metric system for recording distances. American or British?Ģ0/20 is actually an American measurement. Or at 20 feet they can see something that someone with normal vision can only see if they move closer to the chart, 10 feet. Someone with 20/10 vision, means that on the standard letter chart they can see three lines of letters smaller than someone with normal vision. There are quite a few people who can see better than 20/20, and their vision might be documented as 20/10. Someone whose vision is worse than “normal” may have their vision documented as 20/30, meaning at 20 feet they can identify letters that someone with normal vision would see at 30 feet. ![]() So if your eye care practitioner says you have 20/20 vision, it means at a distance of 20 feet, you can accurately identify the same sized letters as someone with “normal” vision. Visual acuity is the clarity or sharpness of vision when measured on a standard letter chart. People use the term 20/20 vision a lot, and they tend to think it means “perfect vision”, but it actually means “normal visual acuity”. But what does it mean to have 20/20 vision? The year is 2020, there are vision related puns and memes all over the internet.
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