A London-based group of doctors recently found that smartphones cause blindness when they are used at night. The conclusion was drawn after two women, ages 22 and 40, experienced ‘transient smartphone blindness’ for several months which occurs when people look at their smartphones with one eye. The women complained of repeated episodes of temporary vision loss that lasted for up to 15 minutes. They were subjected to variety of medical exams, MRI scans and heart tests, yet doctors could not find anything wrong with them to explain the problem.

The patients were referred to an eye-specialist where they were observed in a neuro-ophthalmic clinic. The patient’s history revealed that these symptoms appeared only after using smartphones for several minutes in the dark while lying in bed. Both patients were asked to experiment and record their symptoms. They reported that the symptoms were always in the eye opposite to the side on which the patient was lying which meant that both women typically looked at their smartphones with only one eye while resting on their sides in the dark while their other eye was covered by the pillow. The details of the transient smartphone blindness phenomenon were published in the New England Journal of Medicine today.

Dr Gordon Plant of Moorfield’s Eye Hospital in London, the doctor who treated the women, simply asked them what they were doing at the time the symptoms appeared. According to Dr Plant, both women were looking at their phones with one eye while lying in bed in the dark, while the other eye was covered by the pillow. This caused one eye to be adapted to the dark while the other eye adapted to the light. Dr Plant further added that when the women put their phones down they could not see from the eye they used to look at their phones because one eye was taking a few minutes to catch up to the other eye which had already adapted to the darkness.

Dr Plant cleared the air of any mystery surrounding the women’s condition since transient smartphone blindness is temporary. One of the women was relieved the short-term blindness did not point towards a more serious problem such as a forthcoming stroke. Dr Plant stated that the second woman was more doubtful and kept a diligent diary for several months, tracking her eye vision levels before she was finally convinced of the findings. However she still could not stop herself from using her phone in bed at night.

Dr Rahul Khurana, MD, a vitreoretinal surgeon at Northern California Retina Vitreous Associates Medical Group, and a spokesman for the American Academy of Ophthalmology, said that it was a compelling conclusion but believed two cases were not enough to prove that one-eyed smartphone use in the dark was the root of the problem. He also remained unconvinced that many other smartphone users would experience the same problem.

Khurana, who admitted to being a smartphone addict, said that he and his wife recently tried to recreate the situation, but had difficulty checking their phones with only one eye. “It was very odd,” he said.

Although most people view screens using both eyes, there are many people who frequently use smartphones while lying down, when one eye is accidently covered. Smartphones are now used nearly all the time, and manufacturers are producing screens with increased brightness to offset background ambient luminance and thereby allow easy reading. Hence, cases such as these are only going to become more common.

The results of the study show that detailed history tracking and an understanding of retinal physiology can ease the minds of both patients and doctors and can prevent unnecessary stress and expensive investigations. Smartphone addiction is to be blamed for this phenomenon and could have been easily avoided if smartphone use was limited to before going to bed, by following a daily smartphone use routine.

Currently, there are 2.5 billion smartphone users in Asia. According to Yahoo, the number of hardcore mobile users has risen by 60% over the last year. Another report says that an average Briton checks his phone 50 times a day. Americans, on the other hand, spend an average of three hours, 40 minutes on their phones every day, which is an increase of 35% from 2014.

Smartphone addiction can take a toll on our mental and physical health. It is making our generation reclusive and distant – children these days are becoming more focused on their smartphones than studies, friends or sports.

According to a report by the USA Today, thereare an estimated 280 million smartphone addicts in the world, the majority of whom are, of course, teenagers and young adults. Compared to the time when mobile phones were newly launched, the trend of being fixated to one’s smartphone has increased significantly — users spend as much as 96 minutes per day on their phones.