Role of environmental factors in pathogenesis of myopia: definite data, hypothesis, controversies

Although the exact cause of myopia is still not known, it is well accepted that it is a multifactorial condition involving both genetic and environmental components. Even if myopia is characterized by positive family history, no specific genes have been found to be associated with physiologic myopia. It could be thought that heritability is the result of both shared environments and shared genes. In our review, we analyzed the main environmental factor that could be involved in myopia (near work, accommodation, refractivity adjustment, intelligence quotient, light levels exposure and dietary factors) focusing on definite data, hypothesis and controversies about them.