Some years ago, my friends and I were sitting in a lecture when out of the blues one of them noticed how much I was squinting just to read the PowerPoint slides. I brushed her comment as thought thoughtlessly and carried on paying attention to the lecture. It was not until recently that I got into a car accident which opened my eyes to this visual defect I possessed called 'Myopia'. Sure, I sat the driving test four years ago which was accompanied by a vision examination and I past with flying colors, yet many people like myself are unaware that vision can change quickly over a short period of time. This article is simply written to define myopia and explain how it arises. Hope you enjoy and understand it
What is Myopia? Myopia is simply defined as' short sightedness or 'near sightedness'. As the term implies, people are not able to see distant objects because the images appear blurry and fuzzy so their eyes are only capable of seeing objects up close. The retina is a structure of the eye which is analogous to a movie screen since everything we perceive in the real world falls on this anatomy. Anything which falls in front or behind the retina (movie screen) will not be in focus therefore in the case of myopia; parallel light rays from distant objects come to focus in front of the retina producing blurred images. To compensate for this condition wearing negative power contact lenses or glasses allow people to reach '20/20 acuity' or 'normal vision'.
How does myopia arise? Myopia arises from a mismatched between the refractive power of the eye and its axial length or its abnormal cornea curvature. The length of the eyeball is too long for its eye's power or the cornea (the transparent outermost structure of the eye) is too flat and has lost its correct curvature. It has been heavily debated for years whether its cause is of 'nature or nurture'. Strong supporting evidence show that myopia can have a genetic constituent or occur as a result of environmental influences. If short-sightedness arises during infancy or preschool years of a child then this proves that there is a strong heretitary component but if myopia presents itself later on in life then there is a greater possibility of an environment influence on this condition since the greater opportunity for preventive measure.