Myopia (nearsightedness) is essentially 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 characterized by the fact that it gets worse over time. 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. In this case, the furthest point that a person can still see in sharp focus is just eight centimeters from the eye. Normal everyday life without visual aids is then no longer possible.
- Pathologic myopia is characterized by pathological manifestations such as complication in the fundus (for example, retinal detachment—see below). Pathologic nearsightedness is more likely to occur in eyes with high myopia, though this is not inevitable.11