So what exactly is 20/20 vision? It is based on the Snellen chart which you’ve seen in about every doctor’s office on hanging on the wall. The Snellen chart displays letters of progressively smaller size starting with a large “E” on the top and each line gets smaller and smaller.
“Normal” vision is 20/20. This means that the test subject sees the same line of letters at 20 feet that a normal person sees at 20 feet. 20/40 vision means that the test subject sees at 20 feet what a normal person sees at 40 feet. Another way of saying this is that a person with 20/40 vision has vision that is only half as good as normal – or, objects must be at half the normal distance for him to see them.
- 20/20 – Normal vision. Fighter pilot minimum. Required to read the stock quotes in the newspaper, or numbers in the telephone book.
- 20/40 – Able to pass Driver’s License Test in all 50 States. Most printed material is at this level.
- 20/80 – Able to read alarm clock at 10 feet. News Headlines are this size.
- 20/200 – Legal blindness. Able to see STOP sign letters.
Today’s toolbox talk is about a tool you can utilize to help you maintain good vision. This is especially true for those who work continually on computer screens and other interfaces that can cause eye strain. Jobs like data processing, data entry, computer programming, proofreading, designing and the like are particularly susceptible to eye strain due to the focus on a computer screen or other interfaces with smaller, detailed items. So when doing these tasks think about preserving your 20/20 vision with what is called the 20/20/20 rule.
The 20/20/20 rule, if followed, helps reduce fatigue and eye strain. It is pretty simple and states: Every 20 minutes, take at least 20 seconds and look away from your work/screen and focus on something else that is at least 20 feet away from you. Seems like a pretty simple rule but it can be very effective in reducing the strain on your eyes by taking that short break every 20 minutes. In addition it is suggested that you take this little mini-break to do the following to help reduce muscle fatigue throughout your body:
- Get up out of your chair
- Blink your eyes rapidly to propagate tear production
- Stretch your legs and arms
- Walk around if you are able
- Turn your neck and move your shoulders around.
Try this the next time you find yourself spending a lot of time in front of the computer screen. Take a 20 second break every 20 minutes, stretch and look at something else at least 20 feet away.