Nearsightedness

Nearsightedness is increasing worldwide. It is often assumed that nearsighted parents will have nearsighted children, but it is not that simple. External factors play a significant role. How much time children have spent outdoors seems to have a major influence on the development of their eyes.

In recent years, it has become common knowledge that excessive screen and smartphone use, especially among children and adolescents, has led to a significant rise in nearsightedness. The clearest data sets come primarily from Asia, but these trends can no longer be denied in Europe either. For example, in China, more than half of all schoolchildren are already nearsighted, and in Germany, about one-third of the total population is affected.

Myopia, or nearsightedness, is a deformation of the eyeball lengthwise. In a healthy eye, light is focused on the retina, whereas in myopia the focus lies in front of the retina — resulting in blurry vision. An elongation of just 1 mm corresponds to approximately 2.7 diopters. Myopia usually develops between the ages of 8 and 15, and the earlier it develops, the stronger it tends to become. It should also be noted that high myopia carries risks of secondary diseases such as glaucoma, cataracts, or retinal detachment.

Short distances between the screen and the eye, a fixed gaze, and reduced blinking contribute to eye problems, but lighting conditions—both from the screen and the environment—also have an effect. We have already covered screen light in one of our blog posts; here we want to focus mainly on ambient light.

Most adults are exposed to a mixture of natural and artificial light during work, as most jobs today take place indoors. However, it must be considered that most children and adolescents also spend much of their day, if not the entire day, indoors at school or kindergarten.

Another reason for the high increase in myopia among children is the rising academic pressure, already present in elementary school. The close distance to books and increased study time are major factors. It is recommended to maintain a minimum distance of 30 cm and to take regular breaks, at least every 30 minutes.

Research is still divided on whether reading on paper or playing computer games strains the eyes more. The fact remains that the overall duration is what matters.

Just as looking into the distance provides a healthy contrast to short screen distances, it is important to expose our eyes to natural light daily. Several studies show that the amount of daylight exposure largely determines whether myopia develops and progresses. Researchers estimate that just 40 minutes of daily outdoor time can reduce the risk by a quarter. This is mainly due to the dopamine levels in the retina, which prevent the eye from elongating. The effect is strongest when spending more than two hours outdoors. Therefore, it is recommended: spend as much time outside as possible and play outdoors with children! It is healthy for the eyes and the body.