Digital eye strain, a growing concern

Read time 4min 10sec
Every digital device screen is a source of high-energy blue light which can cause
digital eye strain, says eye experts.
Every digital device screen is a source of high-energy blue light which can cause digital eye strain, says eye experts.

More and more people are using smartphones, laptops, tablets, e-readers, and other electronic devices with visual displays. As a result of increased accessibility to these devices 50-90% of people using them globally will experience digital eye strain (DES) at some point in their lives.

This is according to Dr Ismail A Dindar, ophthalmologist at Intercare Sandton Day Hospital. He says due to living and interacting in a digital world, more people are spending most of their time on digital devices.

"DES is caused by a combination of factors such as uncorrected far-sightedness or presbyopia, ocular surface disease, long periods of uninterrupted focus on a computer screen or any device with a digital screen and inadequate positioning or lighting," he explains.

Our eyes and brain react differently to characters on a computer screen or smartphone screen than they do to printed characters, he says, and this is the fundamental cause of DES.

According to health Web site, the average number of hours most people spend in front of an electronic device is between 7.4 to 9 hours a day. Every single device is a source of high-energy visible (HEV) artificial blue light which can cause serious long-term damage to your eyes when exposed to it for long hours on end.

Gunners says when we glare at a digital screen, words and images are created by combinations of tiny points of light (pixels), which are brightest at the centre and diminish in intensity toward their edges. This makes it more difficult for our eyes to maintain focus on them. Instead, our eyes want to drift to a reduced level of focusing called the "resting point of accommodation" or RPA.

Our eyes involuntarily move to the RPA and then strain to regain focus on the screen. This continuous flexing of the eyes' focusing muscles creates the fatigue and eye strain that commonly occurs during and after computer use.

Last month The Vision Council released a report examining the impact of digital media on vision health. The report found one in 10 people spend at least three-fourths of their waking hours on a digital device, and that prolonged periods of use appear to exacerbate symptoms as 96% of Americans who experience digital eye strain spend two or more hours each day using smart devices.

In an effort to educate avid digital device users, the council introduced computer glasses to alleviate vision problems and protect eyes from blue light, glare and other environmental stressors.

"When using technology, many people think suffering with digital eye strain is unavoidable, but it doesn't have to be," says Mike Daley, CEO of The Vision Council.

"The optical industry has responded to the shift in digital habits and has developed lens technology to protect eyes from blue light, glare and other environmental stressors," adds Daley.

However, despite concerns that staring at devices containing high amounts of the blue light wavelength could damage human retinas, a recent study by the Laser and Optical Radiation Dosimetry Group of Public Health found that most devices put out less of that light than the blue sky on a clear day.

"Even under extreme long-term viewing conditions, none of the low energy light bulbs, computers, tablets and mobile phones we assessed suggested cause for concern for public health," said lead author John O'Hagan, head of the Laser and Optical Radiation Dosimetry Group of Public Health England in Chilton, UK.

The researchers of the study pointed out in the journal Eye that, as people are using computers and phones more often, and low-energy lighting like fluorescent and LED bulbs is becoming more common, the types of light human eyes are encountering is also changing.

To avoid risks associated with DES, Dr Dindar advices the 20-20-20 rule is one of the few effective preventative measures one can use.

"The 20-20-20 rule entails taking 20 second breaks looking at a distance of at least 20 feet every 20 minutes of digital work," he explains.

He adds ensuring adequate light positioning is vital in preventing glare which worsens DES.

"One way of achieving this is by using anti-glare glasses which protect the eyes against the strain caused by HEV light."

He reveals these glasses have lenses and filters customised to reduce blurriness and pixilation, decrease brightness, block blue light, and minimise glare while working in front of a screen - or multiple screens.

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