Digital eye strain is the ocular discomfort felt after two or more hours in front of a digital screen and is associated with the close to mid-range distance of digital screens, including desktop and laptop computers, tablets, gaming consoles, e-readers and smartphones.

This includes what was previously referred to as Computer Vision Syndrome, when the other newer gadgets were not available.

Demographics

A recent study published by the American Optometrists Association shows that almost one-third of adults spend more than half of their waking hours( 9+) using a digital device. In addition, almost 80% kids use their device on an average of 3 hours per day.

In our urban Indian population too, though there is no proper data available, it is likely that the numbers would be similar.

Currently, use of digital devices is a family affair, with almost all family members using them for most of their daily activities like work, study, shopping, watching videos, playing games etc. There is no restriction of use and this is habit-forming and addictive.  Also most people are ignorant about the damage caused by these unhealthy practices and it is a very convenient way to keep children occupied for parent’s selfish motives. The purpose of this article is to highlight various ocular side effects that could be related to overuse of these gadgets, their causes, symptoms, treatment options and preventive measures.

Symptoms

Most common symptoms include pain in eyes, headache, brow ache, watering, blurring of vision, double vision, tired eyes, and grittiness or burning sensation in eyes.

Causes

These include poor lighting, reflected blue light, glare on a digital screen, improper viewing distances , poor seating posture , uncorrected vision problems  or  a combination of these factors.

The display screens of computers, electronic notebooks, smartphones and other digital devices emit significant amounts of blue light. The amount of blue light these devices emit is only a fraction of that emitted by the sun, but the amount of time people spend using these devices and the proximity of these screens to the user’s face can have possible effects on a person’s eye health. Closer the screen is to the eyes and longer the time duration of use, more are the ocular side effects.

Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused. This unfocused blue light causes reduction in contrast and impairs visibility leading to eyestrain.

Also, continuous staring at the screen causes eyes to remain open wide for long periods of time with infrequent and incomplete blinking. This causes improper spreading of the tear film with resultant dry eye symptoms. Continuous use without proper refractive correction can also cause squinting and problems with eye accommodation leading to blurring of vision.

Other related factors:

The extent to which individuals experience visual symptoms often depends on the level of their visual abilities and the amount of time spent looking at a digital screen. Uncorrected vision problems like farsightedness and astigmatism, inadequate eye focusing or eye coordination abilities, and aging changes of the eyes, such as presbyopia, can all contribute to the development of visual symptoms when using a computer or digital screen device.

Though we have many problems related to the use of digital devices, it is heartening to note that most of the visual symptoms experienced by users are only temporary and will decline after stopping computer work or use of the digital device. However, some individuals may experience continued reduced visual abilities, such as blurred distance vision, even after stopping work at a computer. If nothing is done to address the cause of the problem, the symptoms will continue to recur and perhaps worsen with future digital screen use.

Treatment options: Many options are currently available, especially for people who cannot cut down on their usage of digital devices.

1) Special spectacle glasses ( computer glasses) with yellow-tinted lenses can increase comfort while viewing digital devices for extended periods of time. These special-purpose lenses can be used with as well as without prescription glasses.

2) For people who use their phone constantly – especially if used primarily for texting, e-mailing and web browsing – a convenient way to reduce blue light exposure is to use a blue light filter. These filters are available for smartphones, tablets, and computer screens and prevent significant amounts of blue light emitted from these devices from reaching the eyes without affecting the visibility of the display. Some are made with thin tempered glass that also protects the device’s screen from scratches.

3) Also, a number of lens manufacturers have introduced special glare-reducing anti-reflective coatings that also block blue light from both natural sunlight and digital devices.

4) Especially with use of computers, several guidelines are available to maximize eye comfort with continuous eye use. This includes lighting conditions, chair comfort, location of reference materials, position of the monitor, and the use of rest breaks. The most important and easily implementable of these is the 20-20-20 rule . Every 20 minutes, the user is encouraged to take a 20-second break and focus his/ her eyes on something at least 20 feet away. This prevents continuous staring, promotes complete blinking and reduces eye strain as our focus changes intermittently. This rule can  be extrapolated to other gadgets too.

5) In addition, symptomatic treatment in the form of tear supplements can provide temporary relief. Also proper use of spectacle correction as required will reduce strain on the eyes. Hence a complete eye checkup by a specialist is warranted in all such cases.

But, as it is always said, prevention is the best medicine. Reducing the time we spend on digital devices and taking meaningful breaks can go a long way in saving our eyes from unnecessary torture. Improving awareness in adults and inculcating good habits in children are the need of the hour. Children should not be made to depend on gaming consoles or smart phones to spend their free time, instead outdoor physical activities should be included in their daily routine.

Inputs by Dr Minu Ramakrishnan, Professor and Head, Department of Ophthalmology, K J Somaiya Hospital and Medical College.