Myopia is the refractive error that results when an imbalance of the eye structures responsible for creating an accurately positioned focal point of a faraway object (corneal power, lens power, and eyeball length) causes this point to be focused in front of the retina instead of on the retina.
Myopia is also known as "near sight", because when an object is brought nearer to the eye, the focal point moves back toward the retina until at some point (depending on the amount of myopia) the near object becomes focused on the retina without any effort from the focusing muscles, and the person has "near sight".
