Myopia Development in Infants :: Vision Sight Nearsightedness Disorders Essays

Myopia Development in Infants An impairment in vision can lead to a very challenging life. Many Americans suffer from abnormalities in their vision. They suffer with diseases such as glaucoma, hyperopia, and myopia. Myopia, or nearsightedness, is fairly prevalent in the United States of America. In fact, it is estimated that twenty-five percent of the population of the United States is nearsighted (Kolata, 1985). Myopia occurs when the resting eye becomes focused on distant objects. The lens of the eye must become thicker and the radius of curvature must be increased in order for the eye to look at nearby objects. In individuals with myopia, the eyes are excessively long. This causes the image to form in front of the retina as opposed to on it (Kolata, 1985). Myopia frequently results from excessive postnatal eye growth. Typically, it develops in the early school years; however, some cases do not develop until early adulthood (Quinn, Shin, Maguire, & Stone, 1999). Myopia is a very serious disease that can have a tremendous effect on the life of a child. Approximately 5.6% of blindness among American school children can be attributed to myopia. Furthermore, it predisposes individuals to retinal detachment, retinal degeneration, and glaucoma (Quinn et. al., 1999). The cause of myopia has not yet been determined. However, children of parents with myopia tend to develop myopia more frequently than children with nonmyopic parents (Young et.al., 1998a). The two highest factors that contribute to myopia are myopic parents and doing "near work". Other indications for the development of myopia include childhood illnesses, low birth weight, and nearsighted siblings (Review of Optometry, 1999). Since a definite cause for myopia has not been determined, researches are divided as to whether the disease is caused by genetic factors or environmental factors. The debate for the genetic theory begins with the thought that myopia may be due to a dominant gene that is inherited by the child from the parent (Young et.al., 1998a). There is evidence to suggest that genetic heterogeneity attributes to high myopia ( Young et.al., 1998b). This implies that the child who inherits diversified genes from his or her parents is more likely to develop myopia. However, it is also thought that myopia may be caused by influences from the nervous system that are not normal and have a negative impact on the developing eye. Thus, it may, as well, be genetically determined (Kolata, 1985). The basis for the genetic theory is supported by the fact that myopia tends to run in families.