Myopia or nearsightedness is the most common vision problem in the world. It is estimated that the number of people affected with this condition worldwide, amount to about 1.6 billion, and this figure is expected to touch 2.5 billion by the year 2020. Myopia is characterized by an inability to see things clearly at a distance. The underlying defect is a failure of the eye to focus the image on the retina, instead focusing it right in front of the retina. This effect, itself could be caused either due to the eyeball being longer than the optical length of the eye, or due to an increased curvature of the cornea. In most cases, the condition develops in children in their teens, and progresses through their growing stage. The progression of the disease usually stops once the individual is in the early twenties.

Myopia is suspected in individuals who see images at a distance in a blurry fashion. The condition can be confirmed upon evaluation by an ophthalmologist or optometrist. The condition can be easily managed by wearing eyeglasses or contact lenses, which correct the fault in curvature. Surgical corrections for myopia are also now available. The most popular of these is LASIK, which utilizes an excimer laser to reshape the cornea, thereby correcting the defect.

There is an ongoing debate as to whether myopia develops as a result of genetic or environmental influences. Supporters of the genetic nature of the condition cite the extreme variability in prevalence of the condition in different ethnic groups as a credible evidence. It is fairly clear, however, that at least the severe levels of myopia tend to be hereditary.

Several different loci have been identified with myopia. MYP2 is mapped to chromosome 18p. TGIF (TGF-beta-induced factor) gene, mapped to chromosome 18p, is considered as a probable candidate gene for high myopia. Both COL2A1 (Collagen Type II Alpha 1 Chain) and MYCBP2 (MYC Binding Protein 2) have been reported to be associated with high-grade myopia.