When 30-year-old Manju began seeing floaters and dark zigzags, she put it down to tiredness and ignored it. After a few months it became a regular occurrence. She also began seeing bright flashes. Still, she ignored it. But, after a year it became more frequent and, at times, she was unable to see or focus on objects. Finally, Manju (name changed) decided to consult an ophthalmologist and was referred to a neurologist.
Dr Sudhir Kumar, senior consultant neurologist, Apollo Hospital, Hyderabad, diagnosed her with smartphone vision syndrome. Manju, who was a factory employee, quit her job after she had a baby. Her husband would return from work late and Manju would stay awake till he was back. While waiting for him, Manju would switch off the lights, lie down beside her baby and watch videos on her smartphone for hours. She never thought the screen brightness, changing colours and the darkness in the room would do her harm.
Manju is among 1.8 crore people in India affected by dry-eye syndrome or computer vision syndrome (CVS). In one year, at least 30,000 children under five complain of blurred vision. While malnutrition and consanguineous marriages are two of the reasons for the increasing cases of blurred vision in children, another major reason is prolonged smartphone screen time.
The symptoms include floaters and zigzags, burns around the eye, non-stop tears or complete, momentary blindness. Additional symptoms could be pain in the head and neck. CVS, according to ophthalmologists and neurologists, does not lead to permanent vision loss but causes vision disturbance. There could also be redness, pain or watering in the eyes.
“The only reason for this is more screen time and the brightness on the screen,” says Dr Niveditha Narayan of Sankara Nethralaya in Chennai.
Dr Ravindra Mohan of Trinethra Eye Care, Chennai, says we have to learn to live with it because the cause is lifestyle related. “The job of the eye is to convert light impulse into electrical impulse, which will travel along the nerves to the brain,” says Mohan. “This is the system which is used to touch and feel the real image. This is called the eye-nerve-brain coordination.” He says that digital screens lead to people of all ages stressing out their eyes and nervous systems.
“The longer the use, the more the stress,” says Narayan. Sankara Nethralaya has a dedicated CVS clinic. Patients who walk in every day for treatment range from five year olds to 80 year olds. “The footfall in the clinic has been increasing day by day, sounding an alarm,” says Narayan. She says that most patients do not blink enough when they do visually strenuous work. “That is a natural phenomenon,” she adds. “When somebody is keenly listening to or watching something, they do not blink and the eyes get bulged.” The blinking rate comes down by 50 per cent in such situations. The reduction in blinking and the air in air conditioned rooms cause dehydration, leading to dryness in the eyes.
In the case of Manju, CVS occurred because she used her phone with the lights off. Looking at the bright screen in the dark room caused her retina to be under the maximum pressure. “I advised her to reduce screen time,” says Sudhir Kumar. “She was anxious, but, with counselling she was alright. She [reduced] her phone usage. After one month, the symptoms started subsiding. She is fine now.”
He cites the case of another patient who used to cover one of her eyes with a bed sheet and look at her phone with just one eye. “This is even more dangerous,” he says. “We tell patients to split work into portions and not to use digital screens during breaks.” The usual advice is 20-20-20―every 20 minutes, look 20 feet away for 20 seconds. However, with the increase in use of digital screens, ophthalmologists say CVS cannot be eliminated, only managed.