So is the Crystalline
The crystalline is a biconvex lens located inside the eyeball, between the iris and the vitreous body.
This structure is one of the main components of the "dioptric system of the eye": thanks to the action of the ciliary muscle, the lens is able to change its shape to "automatically" adjust the focus of the light rays on the retina, based on the proximity or less of the object to be displayed (variation of the refractive power). This capacity is physiologically reduced with age, when presbyopia arises. The lens also undergoes changes in thickness, elasticity and transparency.
