Excessive use of digital devices can cause ophthalmic problems ranging from eye strain to myopia, especially in younger children – Aruna Raghuram
Digital screen-based activities dominate the lives of 21st century children. Computers, smartphones, video games and television are taking precedence over playing outdoors, sleep and family time. Children who have barely completed toilet training are glued to tablets and smartphones for recreation if not learning.
It’s well known that excessive screen time can cause obesity, repetitive stress injuries, cognitive decline, aggression, social isolation, addiction and even depression in children. It can also majorly impact the visual health of children.
According to the American Optometric Association, the imprints on a computer or handheld device are not as sharply defined as print on paper because glare and reflections on the screen make viewing a strain. Moreover, viewing distances and angles tend to differ from normative non-digital reading and writing. That’s why, eye focus and movement requirements for digital viewing impose additional strain on visual systems.
A 2009 study ‘Impact of computer use on children’s vision’ published in a Greek journal Hippokratia highlighted that children are more susceptible to vision problems while using digital devices because they are less self-aware (they may forget to blink or take breaks), more adaptable (they are likely to ignore vision problems) and use adult computers which are not suitable for children.
During the past decade, ophthalmologists worldwide and in India, are reporting a sharp rise in the number of children diagnosed with myopia and short-sightedness. Parents should be especially alert and look out for the warning signs. Children suffering myopia are likely to insist on being seated in the front row of classrooms, complain of headaches, tired eyes, and tend to constantly rub their eyes.
Though genetics plays a big role in the development of myopia in childhood, research suggests that digital eye strain is also a major contributory factor. When children are using digital devices, their eyes have to exert effort to focus. Fatigue caused by excessive eye strain leads to changes within and prompt myopia. Comments Dr. Jameel Rizwana Hussaindeen, head of the vision therapy clinic, Sankara Nethralaya, Chennai: “Overuse of digital devices strains eye muscles. This, in turn, can cause short-sightedness that is either temporary or can become permanent. Spectacles will restore vision, but if a child gets myopia at a young age, there is always the risk of progressive deterioration.”
Visakhapatnam-based retina specialist Dr. Divya Chandran warns that prolonged play of video games by children below ten years is more harmful to visual health than other screen-based activities. “As video games require high-speed and repetitive action, they cause greater visual strain than other digital devices. Since they require quick responses to speedy images, they overwork the dominant eye. This can cause refractive errors and also eyelid tics,” she says.
Computer vision syndrome
Computer vision syndrome (CVS) is a group of vision-related ailments caused by continuous viewing of an electronic display screen. Poor lighting, glare from the screen, incorrect posture and improper viewing distance aggravate the eyes. The symptoms of CVS are dry eyes, hazy vision, prickly eye sensation, redness, tearing, irritation, headache, dizziness, eyelid tics, light sensitivity and neck and back pain.
“Viewing digital screens for long periods adversely affects overall eye health. The ciliary muscle — which works to focus objects on the retina and the iris and also regulates the amount of light entering the eye — is strained because of the difference between screen brightness and the surroundings. This is more so in poorly lit rooms. Moreover prolonged screen focus causes poor blink rates. Normatively we blink 12-14 times per minute. Among habitual digital screen viewers, this reduces to four-six times per minute. All this leads to ocular fatigue and eye problems,” says Dr. Y.L. Rajashekar, founder-director Shekar Eye Hospital, Bangalore and vice-president of the Karnataka Ophthalmic Society.
Towards healthy vision
Consequently ophthalmologists are almost unanimous that parents should limit screen time of children, encourage outdoor play, insist on regular eye check-ups, and supplement this by providing healthy balanced diets. “Nutritional deficiencies during childhood can result in ocular damage. A balanced diet rich in vitamins, minerals and Omega-3 fatty acids is important for eye health. Adequate outdoor physical activity is also crucial because not only does it cut short screen time, it also protects the eyes from developing myopia,” says Dr. Hussaindeen.
Dr. Chandran believes that parents must be vigilant and prompt about regular eye check-ups to detect ocular problems. “First, parents should stop using digital devices as babysitters and limit screen time. Second, I strongly recommend that parents insist on a comprehensive binocular vision assessment to assess the coordination of eye muscles. Excessive screen usage is likely to lead to convergence insufficiency. A binocular vision assessment will detect this condition and simple eye exercises can be advised for children to alleviate eye muscle weakness,” says Chandran.
Screen time recommendations
The Canadian Association of Optometrists/Canadian Ophthalmological Society recommends a maximum of 1-2 hours of digital exposure per day including time spent on cell phones, computer tablets, gaming consoles, iPad etc. Here are its recommendations:
0-2 years. No use of screen media other than video-chatting (e.g, Skype, Facetime)
2-5 years. 1 hour per day, with supervision
5–18 years. 2 hours per day
Preventing digital eye strain
If your child is using a computer:
» Ensure she is seated at least 25 inches away from the computer screen.
» Position the screen so that eye gaze is slightly (10-15 degrees) downward.
» Teach children the “20-20-20” rule — every 20 minutes, look at an object at least 20 feet away, for at least 20 seconds. This combats ‘accommodation spasm’ — when the ciliary muscle of the eye remains in a constant state of contraction because the visual focussing system locks into a particular target distance for a long time and the muscle is unable to relax while viewing distant objects.
» Adjust room lighting so that the screen is not glaringly brighter than the surroundings.
» Palming to relieve eye strain. Warm the palms by rubbing hands together for 15 seconds, then place the palms over eyes, with the fingertips resting on the forehead and palms over the eyes. Hollow the hands slightly. Close eyes, breathe deeply and relax. This exercise helps ease eye fatigue and strain.