There is a positive correlation between asthenopia (or eye strain) and progressive myopia (or the tendency for one’s myopia to become worse). If eye strain is severe, then progressive myopia tends to become worse. Unlike hyperopia, a myopee may not be aware of the progression. The deviation in a hyperopic eye is mainly due to the lens. In the myopic eye, the myopia is due to the eyeball as well as the lens. The eyeball allows extra room for the deviation to set in. It is easier for an excessive “effort to see” to force the crystalline lens and sclera of a myopic eye to become worse almost unnoticed (Yee, 2013b).
Any degree of nearsightedness not only can become worse—but progressively worse. I remember my original pair of glasses was just −0.50 D. At first, I did not wear them all the time, but I was subjected to different types of stress between grade school and high school. My myopia increased rapidly when I started wearing contact lenses. It was not that convenient to take them off when I do not need them for the distance. I was constantly subjected to an overcorrection in the near and midrange. At one point, my prescription deteriorated to −10.00 D. The difficulty with treating higher ranges of myopia lies in the eyeball. It inherits more of the deviation as the myopia gets progressively worse. It is harder to change its curvature compared to the crystalline lens’ curvature.