Myopia, or nearsightedness, is a common refractive error, and is characterized the blurring of objects faraway, while still being able to see clearly up close.

Myopia affects men and women alike. It is generally caused by an elongated eyeball; because the eye is too long, light gets focused on a point in front of the retina, causing objects in the distance to appear blurry.

Another cause can be that the eye ball is too curved and refracts light too strongly, again causing the light to wind up in front of the retina.

Myopia is usually detected at an early age, when a child starts complaining of not being able to read the board, but can easily read books. It is also true that in many cases myopia progressively gets worse until a person stops growing in his or her 20s.

Once a person has been diagnosed, frequent eye checks are essential. Because myopia tends to progress over time, the prescription will change on a regular basis, meaning that new contact lenses or glasses are necessary to accommodate the changed prescription. 

Myopia is partially hereditary, meaning that you're more likely to be nearsighted if one of your parents has myopia. There is no way to prevent myopia.

Glasses and contact lenses easily correct myopia. Also, LASIK surgery is becoming a more common option among adults. However, LASIK it is not recommended for children and teenagers; a person should wait with surgery until they are fully grown.