The 20-20-20 Rule is usually advised to patients who have eye strain caused by prolonged near-work. It’s a sort of eye exercise rather than a ‘rule’.
What Is It?
Every 20 minutes, look away (from the object at close distance) at a distance/object at least 20 feet away for at least 20 seconds.
How Does It Help?
There are two groups of muscles in our eyes: (1) Extraocular muscles and (2) Intrinsic muscles. Extraocular muscles are outside the eyeball and their function is to move the eyes in all possible directions. The intrinsic muscles are found inside the eyeball – sphincter pupillae to constrict the pupil, dilator pupillae to dilate the pupil and ciliary muscle to change the shape of the lens (making the lens more convex).
The muscles in both groups (extraocular and intrinsic) help in focusing at objects at close distance (e.g. reading). When our work involves focusing on or looking at objects at near distance as well as far distance for short periods of time, the muscles of the eyes get the opportunity to ‘relax’ between the periods of ‘work’.
But when we do near-work for long hours, which could be anything like working on computer, reading, writing and so on, the muscles of the eyes go into a phase of constant constriction and if they are in this state for a significantly long time (several hours, for example), then the muscles are obviously strained.
Imagine holding a heavy object in your hand with your arm stretched out horizontally away from your body. How long will you be able to hold it? After a few seconds you will start feeling the discomfort and then pain in your arm.
Similarly when the eye muscles are strained, you feel the heaviness and pain in and around the eyes. You may additionally have tearing, headache and generalized tiredness.
So when you follow the 20-20-20 Rule, you give your eyes sufficient time to relax. The muscles of the eyes don’t go into a state of spasm and you don’t have all those symptoms. 20-20-20 Rule is quite frequently advised to those with Computer Vision Syndrome.
Some Tips and How To Do It
1. Use a timer/alarm application on your computer or phone to remind yourself to follow the rule – especially in the initial phase. Later it may become a habit and then you can use your ‘mind clock’ to follow the 20-20-20 Rule regularly in appropriate situations.
2. Verify the distance from your work table/chair to the object you want to look at. It should be at least 20 feet. If your room is smaller than this, you can choose to look at something outside the window or the door.
3. it’s not difficult to count in your head. Count at least up to 20 slowly. You don’t even have to count necessarily. Your brain knows for how long you have looked away. You know what I mean.
Following the 20-20-20 Rule does not cost you anything but it helps a lot. If your work involves a lot of near-work and you have symptoms of eye strain, try it and you will notice significant improvement in your symptoms.