Are we causing unwanted strain to our eyes by looking at the computer for long periods of time? Is there a way to continue working efficiently at the computer without it having to result in headaches?
There are a variety of solutions to protect your eyes when sitting at the computer. In this two part article, however, we explain steps that you can immediately take to protect your eyes, without having to resort to special light installations or glasses. While these more costly adjustments could be necessary, we first recommend taking these inexpensive steps to reduce eyestrain.
In this article, we charge ourselves with two objectives: 1) to explain why our eyes feel strained after looking at the computer for long periods of time 2) to provide five simple solutions to immediately implement in our daily computer tasks. Part I of this post deals with the first objective, explaining why using the computer can cause eyestrain. Part II deals with finding solutions to this problem.
Why do I develop eyestrain and headaches after using the computer for long periods of time?
In order to understand why we develop headaches and eyestrain after looking at the computer, we first must look at the normal processes of the eye. Two terms, the resting point of accommodation and the resting point of vergance, must be defined and explained in order to know the most neutral position for our eyes.
The Resting Point of Accommodation
Our eye’s adjusts to look at objects at different distances. Eyes accommodate and readjust when viewing items far away and accommodate again when looking at an object close by. In a completely dark room, however, where our eyes are not staring at anything and do not need to adjust for distance, our eyes remain in the most relaxed, neutral position. This relaxed position is called the resting point of accommodation.
Most people prefer staying at the resting point of accommodation. This is the most relaxed position placing the least amount of stress on the eyes. Depending on a variety of factors including an individual’s eye anatomy and age, in order to achieve the resting point of accommodation you should sit, on average, about 30-40 inches from an object.
Resting point of Vergence
In addition to accommodating to various distances, our eyes have the ability to converge or look inward towards our nose in order to allow both eyes to see an items at the same place. The ability to converge on a single object prevents each eye from looking at an item separately, in turn preventing “double vision.”
Just like the resting point of accommodation, our eyes prefer to converge in a most relaxed position. When there is nothing to look at, the eye converges and remains in the most relaxed position called the resting point of vergence. The resting point of vergence is achieved when looking at an item about 45 inches away. However, when gazing downward at about a 30 degrees angle, the resting point of vergence can be achieved at a shorter distance, about 35 inches.
What does this mean for computer users?
For a person sitting too close to the computer screen and away from this resting point of vergence and accommodation, the muscles of the eye become strained viewing the screen at a close distance. This can result in increased eyestrain and headaches. In addition to moving away from the resting point of vergence and accommodation, eye strain can be the result surrounding light or screen brightness, either being too dim or too bright. People will often need to squint to read words on a screen where the surrounding area or the brightness of the screen itself is too bright. Avoiding glare and squinting, trying to read an article in bright light, contributes to eye fatigue and strain.
Click here to see Part II.