Short-sighted people see clearly up close and blurry in the distanceThe “normal” human eye is about 24 mm long. An eyeball that is too long is short-sighted (myopic). If the eyeball is too long, the light rays are not focused on the retinal plane, but in front of it. Therefore, objects in the distance are seen out of focus – 1 millimeter corresponds to a visual defect of about 3 diopters. There is a trend towards increasing short-sightedness (= myopia) worldwide. According to calculations, 50% of all children will be short-sighted in 2030. In many Asian countries such as China more than 80% of all children are already short-sighted.
Short-sightedness (myopia) means: the eyeball grows too much and becomes too long, so that the image is not shown on the retina, but in front of it. In order to see clearly, the short-sighted person needs glasses or contact lenses for correction, the refractive power of which shifts the image back to the retina. From a short-sightedness of half a diopter onwards, details in the distance can no longer be perceived sharply. This is bothersome for many activities, such as driving a car or being in school.
DiagnosisThe most reliable way to diagnose myopia is by an ophthalmological examination at your eye doctor. A simple eye test is not sufficient, as this depends heavily on the cooperation of the child and the result can deviate from the actual diopter values. An exact measurement is only possible through an examination with special eye drops (e.g. cyclopentolate), which prevent the deformation of the lens (accommodation = near focus). As an alternative to instilling eye drops, the length of the eyeball can also be measured for follow-up checks.
The repeated examinations document any increase in myopia and form the basis for therapeutic interventions.
CausesVarious factors such as environmental factors and genetic influences play a role in the development of myopia. In childhood, the eye grows. It has been scientifically shown that daylight restricts the growth of the eyeball and constant close work promotes growth. The oversupply of consumer electronics and daily screen work therefore play a major role. If the eyeball grows significantly, children become short-sighted. This myopia cannot be reversed. A strong myopia of about six diopters or more also lead to other eye diseases: In the course of life, secondary diseases can develop that seriously threaten the eyesight.
Progressive Myopia (Progressive Short-Sightedness): myopia increases at least 0.5 to 1 diopter per year.
Therapeutic interventions for progressive myopia:– Staying outdoors in daylight at least 8-10 hours per week
– Atropine 0.01% -0.05% eye drops given once a day in the evening is one way to slow down the growth of the eyeball. This form of treatment has been successfully tested in Asia in large studies and can be offered to myopic children between six and 14 years if the myopia has increased by at least 0.5 diopters per year.
– Special contact lenses, such as contact lenses with peripheral defocus, are a way for some children to counteract the growth of the eyeball. However, the therapy requires careful, expert support.
– Special glasses (e.g. DIMS glasses: Defocus Incorporated Multiple Segments Eyeglass Lens) are another low-risk option to slow down the progression of myopia.
Risks and side effects:Atropine 0.01% eye drops :
The risks associated with atropine 0.01% eye drops, which have been used for many years, are minimal. Even if atropine (belladonna alkaloid) is toxic in high doses, dilution to 0.01% means that there are hardly any side effects. The application is also carried out under regular supervision by the ophthalmologist and the eye drops can be discontinued at any time.
Contact lensesContact lens wearers generally have an increased risk of infection, which can be reduced to a minimum through precise explanation and training in handling contact lenses and good hygiene.
However, it is even better to take preventive procedures so that a child does not become short-sighted in the first place. Therefore, parents should encourage their children to spend at least two hours a day outdoors - this intervention reduces the risk of myopia. And the time that is spent on close work - i.e. with smartphones, tablets and the like - should be kept within limits.