«Digital native»: generation short-sighted?

Lara loves reading, but she finds it difficult to decipher what is written on the blackboard at school. If she squints her eyes, it gets a little better, but it's exhausting because Lara is short-sighted. This means that the primary school pupil can see well up close, but she can only recognise things further away blurred.
More and more children and young people are feeling the same way as Lara. «From 2000 to 2010, there was a worldwide increase in short-sightedness of almost 30 per cent,» says Dr Vera Schmit-Eilenberger, an ophthalmologist specialising in paediatric ophthalmology and retinal diseases from Dübendorf in the canton of Zurich.

Myopia has reached almost epidemic proportions.

In some countries in Asia and Southeast Asia in particular, short-sightedness, technically known as myopia, has reached almost epidemic proportions. «In parts of China, Singapore and Taiwan, up to 90 per cent of young adults are already short-sighted,» says Vera Schmit-Eilenberger.

Every second «digital native» is short-sighted

Around 60 years ago, the proportion of short-sighted people in the population here was still around 10 to 20 per cent. However, myopia is also on the rise in Europe and the USA. In the USA, the number of short-sighted people has risen by 66 per cent in the last 30 years. According to a study presented by the European Eye Epidemiology Consortium in 2015, a similar trend can be seen in Europe: almost one in two people in the 25 to 29 age group - i.e. the «digital natives» - are already short-sighted.

The higher the level of education, the more short-sighted people there are

For a long time, it was thought that heredity was the main factor in the development of short-sightedness. «To date, around two to three dozen gene loci have been found that are responsible for myopia,» says Vera Schmit-Eilenberger. «This means that there is a demonstrable genetic predisposition if the mother or father is short-sighted.»
Nevertheless, the explosive increase in short-sightedness within a few decades cannot be attributed to this. Studies have investigated the influence of environmental factors on the development of short-sightedness. "It has emerged that prolonged close work with the eyes and too little daylight in particular promote the development of short-sightedness," explains the specialist. The Gutenberg Health Study for Germany from 2015 came to similar conclusions, according to which the number of short-sighted people increases with the number of years of education.

Why is there an increasing lack of foresight?

The first symptoms of the onset of short-sightedness often appear in childhood. «Most children still have normal vision until the end of kindergarten,» says Vera Schmit-Eilenberger. «This often changes in primary school. This is why we talk about so-called school myopia, which typically occurs between the ages of 8 and 15.» This is precisely the age phase in which children spend a lot of time indoors reading, writing and learning - i.e. close-up eye work - due to school and homework.
In addition, the use of electronic media in leisure time is particularly popular in this age group. As a result, many children and young people in this country spend up to eight hours a day or more in artificial light in near vision mode. «If the eye is predominantly exposed to visual stimuli that are only a few centimetres away, it will eventually react by growing longer,» emphasises paediatric ophthalmologist Schmit-Eilenberger emphasises. «This happens all the more strongly the longer the near fixation lasts and the closer the fixated object is.»

What protects against short-sightedness?

It is also now known that the lack of daylight plays an important role in the development of myopia. "Recently published studies have identified outdoor activity as a key environmental determinant for the development of myopia," explains Schmit-Eilenberger. Exactly how daylight protects against short-sightedness is not yet clear.
However, daylight is up to 100 times more intense than artificial light, and intense light promotes the release of the neurotransmitter dopamine in the retina. In animal studies on chickens, a connection between dopamine and the length growth of the eyeball was observed, which is why it is assumed that the release of dopamine by daylight slows down the excessive length growth of the eyeball.

«Regular breaks should be taken during close-up eye work.»

Schmit-Eilenberger, ophthalmologist specialising in paediatric ophthalmology and retinal diseases

Once the eye has grown longer and is therefore short-sighted, this step cannot be reversed. It is therefore important to avoid environmental factors that have been proven to promote the lengthening of the eye at an early stage. "This includes children and young people spending as much time outdoors as possible so that the body gets enough protective daylight," advises the Dübendorf ophthalmologist. «Regular breaks should also be taken when working close to the eyes. It's also a good idea to let your eyes wander into the distance.»
It is also helpful not to keep the reading distance too short. «It should be at least 30 centimetres, preferably more,» emphasises Vera Schmit-Eilenberger. A larger monitor, for example, can help here. «Every child from the age of three should also be examined by an ophthalmologist to detect hidden visual defects that can lead to permanent visual impairments after the age of seven if left untreated,» appeals the paediatric ophthalmologist. «The same applies to children shortly before they start school and, of course, when the first signs of short-sightedness appear.»

Does undercorrection help?

As short-sightedness typically progresses, a new visual aid is usually required at regular intervals. This should always correct the short-sightedness as well as possible. «Unfortunately, the myth that progression of myopia can be prevented by undercorrecting glasses or contact lenses still persists,» laments Vera Schmit-Eilenberger. «However, prospective clinical studies show that undercorrection of myopia does not prevent its progression, on the contrary, it can even fuel it.»
A relatively new therapy for the treatment of short-sightedness is the administration of low-dose atropine drops. They are intended to help slow down the increased growth in the length of the eyeball. «In large studies, treatment with atropine actually reduced the progression of myopia by around one dioptre per year,» says the eye expert. «However, after the end of treatment, the positive effect was reversed.»

Ortho-K lenses are designed to temporarily flatten the central cornea and normalise visual acuity during the day.

Another option for slowing down myopia are so-called Ortho-K lenses. These contact lenses are only worn overnight and are designed to temporarily flatten the central cornea in order to normalise visual acuity during the day. «This method is mainly favoured by opticians,» says Vera Schmit-Eilenberger. "However, ophthalmologists criticise the high costs and the risk of infection. There has also not yet been a meaningful, controlled long-term study to confirm the positive effect."

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Short-sightedness - what is it?

Short-sightedness is the most common type of defective vision. In most cases, it is caused by excessive lengthening of the eye. The focal point, i.e. the sharpest image, is then no longer directly on the retina, but just in front of it, so that objects further away are perceived as blurred. Nearby objects, on the other hand, are seen perfectly. If the eyeball is only one millimetre too long, the level of short-sightedness is already around three dioptres. This means that the short-sighted person can only see objects clearly up to a distance of around 30 centimetres. It is also typical for short-sightedness to progress until around the age of 30.

Recognising the first signs early

The following symptoms may indicate the onset of myopia:

• Häufiges Blinzeln und Zusammenkneifen der Augen, um weiter entfernte Gegenstände zu fokussieren 
• Klagen über schlechtes Sehen von weiter entfernten Objekten, z. B. schlechte Sicht an die Tafel
•  Nahes Heranrutschen an den Fernseher, um besser zu sehen 
• Wiederkehrende Kopfschmerzen und Ermüdungserscheinungen