Myopia, commonly known as nearsightedness, is a refractive error where distant objects appear blurred, while close ones remain clear. It occurs when the eyeball is too long or the cornea is too curved, causing light to focus in front of the retina rather than directly on it. This results in difficulty seeing things at a distance. Myopia often develops during childhood and tends to progress until the eyes stop growing. The use of glasses or contact lenses with concave lenses helps diverge incoming light, allowing it to focus properly on the retina, thereby correcting the blurred vision associated with myopia.