Tablets and smartphones

In recent years new technologies have been massively available, particularly to children, raising the question whether tablets and smartphones are harmful to visual development.

A recent UK study determined that 65% of children between the ages of 3 to 7 have access to tablets at home.¹

Indeed, countless digital applications are available with the purpose of educate or simply entertain infants and toddlers.

Some researchers have highlighted the positive influences of tablets in children’s creativity and play skills.²

This technology can also be used as a teaching literacy tool in healthy children, and in autism, as an alternative communicating language.^2,5

However, research has also focused on the potentially harmful effects of tablets and smartphones.

The American Academy of Pediatrics raises awareness on the impact in development of small children who are excessively exposed to digital technology.

There seems to be enough evidence to avoid exposing children under 18 months to this sort of devices. In older children up to 5 years old the use should be restrict to 1h daily, the contents shoud  be didactic and a parental supervision is recommended.⁶

When it comes to health, two recent studies concluded that the use of smartphones is associated with dry eye syndrome in children and the duration of its use is the main risk factor.^7,8

On the other hand, the time children spend playing outdoors has revealed to be a protective factor against dry eye syndrome.^7,8

A retrospective study with 12 patients focused on the influence of smartphone use in the development of acute esotropia in teenagers.

The authors concluded that there was a relationship between the excessive time using of these devices (over 4 hours a day) and the development of acute esotropia.

Reducing the smartphone use allowed the angle of strabismus to be reduced, although some patients required surgically correction.⁸

Increased myopia prevalence until 2050

Estimations predict that world prevalence of simple myopia (22%) and high myopia (2,7%) will double or triple between the years of 2000 and 2050.¹⁵

This rise in myopia prevalence has an enormous impact on a socioeconomic level.¹⁶

Also, the cumulative visual disability should be assessed, which is more likely in high myopia (39%) but is also present in simple myopia (4%).¹⁷

The high prevalence of myopia has already been reported in small children of Eastern Asia. Although ethnic and hereditary factors are involved in the development of myopia, the influence of environmental factors cannot be excluded.^10-14

Until today, no study has evaluated the effects of tablets and smartphones on the refractive status of children, especially myopia.

However, it is well known the role of accommodation in near work activities and also the tendency for myopia to be diagnosed during school years.

Several studies have been conducted to correlate the time spent on near work and the development of myopia.¹⁸ 

Most of these studies consider near work activities as homework, reading a book, playing a musical instrument, using the computer, playing videogames or board games.¹⁸

A systematic review published in 2015 concluded that a longer period of time spent on near work activities, particularly reading, was associated with an increased risk of myopia.¹⁸

If the use of tablets and smartphones could be classified as a near work activity, then the risk of myopia would be applicable, though these gadgets were not included in these  studies. For this reason and given the complexity of this subject, a demand for further investigation with randomized clinical trials is necessary.¹⁹