Why Do People Become Nearsighted?

Fortunately, LASIK and PRK laser eye surgery offer effective ways to permanently correct nearsightedness (myopia). But many wonder why people become nearsighted in the first place. Several theories have been developed. Some people feel nearsightedness is largely genetic. Studies, however, have highlighted environmental factors during childhood that may lead to nearsightedness. Time spent outdoors as a child in particular has been shown to have some protective effect against developing nearsightedness. Some scientists feel this may indicate that adequate vitamin D during growth and development may therefore have a role in preventing or limiting nearsightedness. A new study looked at some other early life factors that increase the risk for becoming nearsighted. This study, conducted in the UK, looked at 1991 identical twins born between 1994 and 1996 as part of the Twins Early Development Study. Interestingly, in this very large study, the level of the mother’s education, a history of maternal fertility treatment, summer birth, and hours spent playing computer games all were associated with an increased chance of development of nearsightedness. As the participants’ lives progressed, socioeconomic status, educational level, and time spent reading by the twin all also were associated with an increase incidence of nearsightedness. This study does not prove cause and effect, but it does highlight some interesting associations. Ultimately, we still are not sure what causes nearsightedness, but we constantly are learning more.

Leave a Reply