Myopia, also known as short-sightedness, is a common refractive error in which you can see clearly up close, but distant objects appear blurred. It occurs because the eye is too long or the refractive power of the cornea and the lens is too strong. As a result, the image of distant objects does not fall precisely on the retina, but in front of it.
In myopia, the prescription is expressed in negative dioptres, for example -2.00 or -4.50. The higher the number, the more severe the short-sightedness and the blurrier distant vision is without correction. Myopia can develop during childhood or puberty and, in some cases, may continue to progress into early adulthood.
The condition is corrected using a negative lens, which slightly disperses the light so that the image falls precisely on the retina again. This can be achieved with glasses, contact lenses or, in some cases, refractive surgery.