Knowing your digital screens



We are in an era where technology is prevalent and electronic devices have become our best friends. Look around you; whether you are on the train, on the bus, or strolling on the sidewalk, everyone else is probably glued to their digital screens and encapsulated in their mini electronic spheres. It is understandable, actually. I mean, all the information we need are easily obtained via a gentle tap or a convenient swipe on the screens of our phones and electronic tablets. Before we get too absorbed by the next breaking headline of the day, do we really know our digital screens well?


Spending long hours in front of your digital screens may be harmful to your eyes. If your eyes feel really worn out after getting them off your electronic gadgets, you may be experiencing what is known as “digital eye strain”.


Digital eye strain occurs when the ciliary muscles (involved in controlling the curvature of our lens) remain contracted for too long. To look at objects clearly nearby, the ciliary muscles in our eye contract to render the lens more convex in order to accurately focus and refract the light onto our retina (located at the back of the eye). The retina houses photoreceptor cells or cells that receive light rays and eventually send signals to the brain.

Digital eye strain also occurs when our eyes must constantly alter the size of our pupils (holes in our eyes that regulate the amount of light entering) in response to bright or dim light. There are two sets of muscles that control the size of our pupils – circular and radial muscles. The constant changes in the brightness of our screens may cause these muscles to contract and relax frequently and this can cause strain to our eyes. Furthermore, screens are reflective and may reflect light rays from other light sources (sunlight, table lamp) if we position our screens in front of them. This also causes our eyes to adjust continuously so that we can see clearly.


Blue light is present everywhere. You have an abundance of blue light outdoors where the sun shines. Back indoors, you have blue light emitting from the electronic gadgets that you own – computers, flat screen TVs, smartphones, tablets, etc.


Blue light is found in the visible light spectrum (remember your ROYGBIV). It has a short wavelength and higher amount of energy. Our eyes are not capable of filtering away the blue light, so most of them enter our eyes and reach the retina. Studies have shown that overexposure to blue light can be adverse to our retina. The photoreceptor cells in the retina may be overstimulated and eventually impaired. This results in retinal degeneration which may ultimately lead to blindness.


Seriously, however attention-grabbing the headlines or gossip news can be, we ought to learn to put our phones aside for a while and look at something that is far away. That allows the ciliary muscles in our eyes to relax and rest. Besides, it reduces your exposure to blue light. So, take a break after 20 to 30 minutes of relentless screen staring so that your eyes can serve you well in the long run.

Alternatively, investing in a pair of computer glasses may help as well. These work for individuals with or without the need for vision correction. Computer glasses help to limit the amount of blue light entering our eyes.

We could also use anti-glare screen protectors or protectors with a blue filter. The former prevents reflection of light rays from other light sources. The latter blocks out blue light and limits their entry into our eyes.

So, let’s protect our eyes starting from today!

article by Eugene Hsu

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