Does the excessive use of screens influence our vision?

Visual fatigue or asthenopia is one of the increasingly frequent causes in our consultations.

Visual  fatigue  is caused by an overexertion of the visual system, and it is more frequent when we spend  long periods of time looking closely,  that is, accommodating (this is what we call accommodative asthenopia). To simplify the situation a bit, we can understand that  our eyes are "at rest" when looking from a distance  (as long as we are well graduated) and "work" more the closer what we are looking at.

Some of the most common symptoms can be itchy, red eyes, discomfort and even eye pain or headache.

On the one hand, the increasingly widespread use of screens for reading (mobile, tablets or computers) only  aggravates these discomforts,  especially if excessive lighting is used on the screen. By blinking less, our tears evaporate sooner.

On the other hand, if we suffer  from an uncorrected refractive  error (ametropia) or our accommodative capacity is insufficient, this visual fatigue will be even more acute.

Visual fatigue is not the same as tired eyes

However, visual fatigue should not be confused with tired eyesight or presbyopia, which is a physiological problem related to age.

As we age, and especially after the age of 40, we all, to a greater or lesser extent, lose the ability to focus at short distances because the lens capsule (which is a lens that we have inside the eye) loses its elasticity.

We begin to notice it, for example, when we try to read a message on the mobile and  we have to move it away to see it properly.  Presbyopia is a refractive defect that cannot be prevented and the only solution is optical correction  with close-up glasses or surgery. 

Presbyopia does not arise or is aggravated by the use of technology,  but the visual requirements of modern life require us to spend more and more hours focusing closely.

Recommendations to avoid the inconvenience of excessive use of screens

If we spend an average of  8 hours a day in front of a screen  and add the hours of mobile use, it is normal for us to suffer from symptoms of visual fatigue.

For this reason, specialists agree that first of all we must wear the  appropriate optical correction  and secondly it is advisable to  rest for a few minutes  and look into the distance every two or three hours.

Eye  dryness  is also one of the main consequences after continuous visual effort looking at a screen, since the blinking speed is lower.

Using  artificial tears  and lowering the light intensity of our screens can improve symptoms.

For its part, the  protective filters of electronic devices  are a myth. Its usefulness has not been scientifically proven and there are many doubts as to whether there are particular economic interests in this regard.

The  Spanish Society of Ophthalmology (SEO)  issued an official statement on July 20, 2017 that said: “ After a thorough analysis of the existing scientific literature on the subject, current scientific evidence does not show that blue light damages the eye and the benefit of blue filters in the prevention of eye damage by said light radiation. There are no human studies needed before a definitive recommendation can be made about the harm from blue light emitted by display screens (…) .”

Therefore, although the need to carry out such research to establish population health measures seems reasonable, it is currently  not possible to recommend the use of blue light protection screens  such as Reticare to avoid undemonstrated damage in real conditions and in humans by these devices.

How do screens and new technologies affect children's vision?

According to recent studies, in addition to genetic factors, there is increasing evidence that  myopia  is related to environmental factors, such as excessive close-up work. Outdoor activities have been shown  to decrease the likelihood of the development and progression of myopia.

Hence, the importance of trying to limit the excessive hours of close vision (especially in myopic children),  study at a good working distance,  with good light and, if possible, relax your eyes from time to time looking towards infinity.

It is advisable to carry out  annual ophthalmological examinations  for children from the age of 3 or even earlier if we suspect any visual anomaly or if there is a family history of eye pathologies.

It is essential, on the other hand, to rule out that children have  a lazy eye , since we can only treat it at an early age.