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  Is your display safe for the eyes

Is your display safe for the eyes

| FRANCIS D’SA
Published : Sep 22, 2016, 2:03 am IST
Updated : Sep 22, 2016, 2:03 am IST

Every display out there, including smartphone, television or computer, can cause eye strain; staring at the screen constantly is harmful for the eyes.

For cover story (1).jpg
 For cover story (1).jpg

Every display out there, including smartphone, television or computer, can cause eye strain; staring at the screen constantly is harmful for the eyes.

There is no way we can avoid the monitor, is there But just be careful. Staring at the screen constantly is not too good for the eyes.

 

What is computer eye strain Every display consists of pixels that emit light from behind. This light flickers at a particular frequency. Along with the flickering light, the display also has a blue light, contrast, brightness and colour issues that causes discomfort to the eye. If your eyes don't rest enough, you could end up with focussing issues, blurred vision and even headaches. So what is the primary reason that causes eye strain Eye strain can be caused by three main problems with the display - flicker, blue light and inconsistent lighting.

Flicker In general terms, the human visual system perceives flicker when there is a significant change in the brightness of light reaching the eye during short intervals. This frequency shifts between lighter and darker light and is defined by the number of times per second the change occurs, called frequency or refresh rate. If the shifts occur at 3Hz (3 times per second), it is highly noticeable. Research mentions we cannot notice these changes even at higher frequency, but the eye can. However, this threshold may vary from person to person. Older CRT monitor refresh rates were lower, but newer LCD monitors have a higher refresh rate. However, they are still considered problematic and cause eyestrain when used over a longer period of time. Flicker in an LCD is basically caused by the backlight. This is because using a DC (Direct Current) to DC for the backlight is not easy to implement and many monitors still use AC (Alternating Current) which has a higher frequency. A study by Kitasato University Japan, School of Allies Health Sciences, established that DC resulted in lower levels of flicker and eye fatigue, thus helping in prolonged use of monitors.

 

Blue light Blue light is the main reason for eye strain. Blue light can be divided into two parts, short and long. Short wavelength 420nm to 455nm blue light is harmful to the human eye and leads to vision-related problems.

Long wave blue light (455nm to 480nm) is proven beneficial to humans and can boost attention, shorten reaction times and affect mood control in the brain.

Inconsistent lighting Shadows and reflections caused by ambient light combined with uneven light from the monitor/TV can also cause eye strain.

Using a display screen against a bright light or window makes your eyes work harder to avoid the excess glare, resulting in eye strain.

 

Hence bright displays in a dimly lit room, switching from dark to bright scenes on the display and such cases are major concerns.

What next When opting for a monitor for your desktop, a television set, or even a mobile phone, go for those that highlight blue light filters and ambient lighting modes. You could opt for brands that use displays from BenQ which specialises in reducing blue light and flicker.

Newer smartphone brands are already helping by using smart sensors for ambient light and changes the display's brightness accordingly. Some smartphones also make use a feature that cuts off the blue light when reading at night. There are also a few TVs and monitors that have blue light filters, ambient light sensors and ambient light producing LEDs built-within the unit itself, available in the market.

 

Though the technology is presently expensive, it is sure to make its way into all future devices in future. However, with most of you presently using older display tech, we suggest you consider these factors and reduce the amount of continuous usage on your phone, computer and TV.