ABSTRACT
When an eye became myopic, the regulatory role switches from the ciliary muscle to the oblique muscles. The change is neurological rather than mechanical. If it was mechanical, the elongation of the eye causes the zonule fibers to become slack when the vertical distance across the middle of the eye decreases after the eyeball elongates. The lens would bulge independent of the ciliary muscle. In the myopic eye, however, the ciliary muscle becomes thicker (due to an increase in tension) before the lens bulges. If the lens bulges due to the elongation of the eyeball, then the ciliary muscle does not need to tighten up (or become thicker); but since the ciliary muscle of a myopic eye is thicker, it suggests that the lens bulges first before the eye elongates—not the other way around. The myopic model provides important information in the theory behind the treatment of myopia. The myopic lens must flatten first before the myopic eyeball can retract.
