Myopia, also known as near-sightedness or short-sightedness, is a refractive state where distant objects appear blurry while close objects appear clear. This occurs because of a mismatch between the axial length and the focusing power of the visual system, causing the image of an object at infinity to focus in front of the retina. Someone who has myopia is called a myope.
Low Myopia is short-sightedness in the range of -3 dpt or below. Most people who develop Myopia throughout their lifetimes are prescribed with glasses in the Low Myopia range initially at around -1 dpt after experiencing Pseudomyopia.
The same basic principles for reversing Lens-induced myopia apply for all ranges of Myopia, however below -2 dpt usually no glasses are needed for close-up work. This means that improvement might slow down because positive stimulus can only come from Distance Vision.
Definitions vary, but more than -5 or -6 diopters is considered high myopia. This category has a higher risk of various eye diseases and should be particularly regular about getting exams from an optometrist.