2nd Place

 

Adesuwa Ero

Ashbury College

Teacher: Susan Wall

 

 

I am one of the three persons in my family that is near-sighted. I always wondered why I was the first person among my siblings to develop myopia. Then, we were told that sitting too close to the television would damage our eyes, however we did not heed to this warning. As I was the only child to express the trait, the fact that I sat near the television did not seem, to me, to be the sole cause of my imperfect vision. I know now, that myopia is a complex trait and its development is influenced by the interaction of multiple genes and multiple environmental factors (Myopia, 2005).

The eye growth is induced by signals which originate from the retina. Hence neurotransmission in the retina is required to control eye growth. Recently, twenty-four new loci were found to contain genes which play vital roles in neurotransmission in the retina. An important gene is GJD2 which connects neuronal cells in the retina, aiding the transfer of molecules and ions. The mechanisms through which these genes stimulate eye growth are not fully understood, but it is known that the more risk alleles an individual possesses, the greater the tendency to develop myopia (Genome wide meta-analyses, 2013).

An environmental factor that affects myopia is the amount of time spent outside. Natural light provides between 28,000 to 130,000 lux of light, while light intensity in a house is said to be less than 1,000 lux. Bright, natural light from the sun activates the release of a neurotransmitter in the retina, dopamine, which reduces undesirable growth in the eye, hence limiting the elongation of the eye (Morgan, G. 2012).