Basically, myopia (nearsightedness) is a form of visual impairment in which light rays entering the eye are focused in front of the retina. The image produced on the retina is blurred when the uncorrected eye looks into the distance and accommodation is relaxed. This optical defect of the eyes is usually caused by the eyeballs being too long. Usually, myopia first occurs in school-age children and does not necessarily lead to high myopia.
- High myopia starts at -5 diopters – depending on the definition.
- Progressive myopia (a special form of nearsightedness) is characterised by the fact that it gets worse over the years. The length of the eye can continue growing for years. This could, for example, lead to values of -12 diopters. In addition to the health problems that this can cause, it also has a very negative effect on daily life. The furthest point that a person in this case can still see in sharp focus is only eight centimeters from the eye. Normal everyday life without visual aids is then no longer possible.
- Pathologic myopia is characterised by pathological manifestations such as complication in the fundus (for example retinal detachment – see below). Pathologic near sightedness occurs more likely - but not inevitably - in eyes with high myopia.11