#istayhome... in front of the screen: the effect of smartphone and PC on our sight
20 March 2020
Article written in collaboration with Dr. Francesco Loperfido, Head of the General Ophthalmology Service OSR, Head of the Occupational Ophthalmology Service for Preventive Medicine, Ophthalmologist of the Vista Defense Commission, Contract Professor at UniSR.
The new directives for the containment of SARS-CoV-2 contagion are changing our communication models in all sectors, from work to education. Among video lessons, smartworking and moments of leisure, we can calculate that in these days we are connected to the screens about 10/12 hours a day! Our eyes are continually put under stress, consequently also influencing posture, attention, sleep-wake rhythm.
Visual defects, different effects
In general, those with a visual defect must wear glasses constantly:
the nearsighted (they see the near objects clearly and the distant objects blurred) tend to get very close to the screen increasing asthenopic disturbances (that is, of eye fatigue due to a work overload of our eyes);
hyperopia (they see badly from near and better from afar) tend to have frequent headaches that force to abandon the position for a few minutes and, sometimes, to move away from the screen;
astigmatism (which causes blurred vision but also deformed or doubled due to a defect in the curvature of the cornea) can be present together with other visual defects and lead to incorrect postures while reading, writing or using the screen. The consequence are headaches, burning eyes, dry eye and sudden tearing, caused by the reduced blinking of the eyelids in front of the screen.
Whatever the defect, it is essential to lubricate the eyes. This foresight especially applies to those who often wear contact lenses, which bear much less than glasses: they dry quickly, sometimes giving cornea problems. It is good practice to look away from the screen every hour.
"Blue light": watch out!
All LCD and LED devices, such as smartphones, TVs and PCs, emit blue light, i.e. a type of short wavelength light, with a higher frequency and energy. The technically invisible blue light directly affects the production of melatonin, interfering with the biological clock and the sleep-wake rhythm, and is one of the contributing factors in being able to determine a maculopathy (or an eye disease involving the "macula", the central part of the retina). Although there are glasses equipped with "anti blue light" lenses, as well as special smartphone apps for filtering blue light, it would be good to avoid using interactive communication systems late at night, in order not to risk spending the night in white!
A correct posture
Finally, another not negligible aspect is our posture. By spending so many hours in front of the screen, we go to overload the cervical vertebrae, especially when we write or read - perhaps lying on the bed, more frequent than imagined - because we hyperextend the neck. Let's learn to sit correctly: eyebrows at the high edge of the screen, or with the inclination of the head parallel to the tablet/smartphone.