Myopia is a condition in which close objects appear clearly, but far ones don't. It is also called nearsightedness. the causes for myopia are both genetic and environmental. It seems to trickle down through generations of families, but there is not a single gene that determines myopia. Some researchers also believe that eye fatigue from excessive reading or holding a book too close to one's eyes can increase the chance of myopia in children. In short, myopia is not purely a genetic problem, it seems to be influenced by a variety of factors that include both genetic predisposition along with behavioral trends.