Improper Smartphone Use In The Dark Can Make You Temporarily Blind

That seemingly harmless habit of yours of using your smartphone before bedtime can give you vision problems. Doctors have warned that two women in the United Kingdom experienced temporary blindness after looking at a bright smartphone screen in a dark room.

The two women experienced short-term vision problems that occur late at night or early in the morning, Live Science reported.  In the first case, a 22-year-old woman said she had difficulties seeing out of her right eye at night and only outlines of objects are visible to her. Her troubles happened several times a week for a year.

The other case involved a 40-year-old woman who couldn't see out of one eye in the early morning before sunrise. The problem persisted for around 15 minutes and occurred intermittently for six months. According to doctors, both of the women's vision problems happened after they stared at their smartphones' screens for several minutes while lying in bed on their sides.

Root Of The Problem

The doctors believe that the women's temporary blindness stemmed from looking at their smartphones with just one eye without realizing it. When a person is lying on his/her side, the other eye gets blocked by the pillow and adapts to the dark, while the other eye looking at the smartphone gets accustomed to the light. After the smartphone goes off, the light-adapted eye becomes "blind" and takes several minutes to recover from its "blindness."

Dr. Rahul Khurana, a spokesman for the American Academy of Ophthalmology, said the recent findings are interesting but noted that two cases weren't enough to prove the dangers of one-eyed smartphone use. Also, he doesn't think that plenty of smartphone users would experience the same temporary blindness.

Using Smartphones Before Bedtime Disrupts Sleep

Using smartphones before bedtime doesn't just affect a person's vision; it can also damage sleep by disrupting the body's natural circadian rhythms. According to Tech Times, smartphones and other electronic gadgets emit blue light that interrupts melatonin, the body's natural sleep hormone.

Electronic gadgets emit blue light during the day so the screen remains viewable throughout the sunshine. At nighttime, the brain gets tricked into believing that the blue light is the Sun and reduces its melatonin production.

Disrupted circadian rhythms can lead to serious health problems, warns Anne-Marie Chang, a neuroscientist and sleep expert at Pennsylvania State University, Live Science reported. This includes cardiovascular illnesses, cancer, diabetes and obesity.

People who look at their smartphones for more than four hours each day are 49 percent more likely to have troubles sleeping at night. Experts suggested abstaining from gadget use one hour before bedtime to avoid sleep issues, The Independent reported.