True or false: The crystalline lens is refractive.

The correct answer is that the crystalline lens is indeed refractive. The crystalline lens is a transparent, flexible structure located behind the iris and the pupil in the eye. It plays a crucial role in focusing light onto the retina by refracting or bending the incoming light rays.

The refractive power of the lens can change due to its ability to change shape, allowing for accommodation—this is the process that enables the eye to focus on objects at various distances. As the ciliary muscles contract or relax, the lens becomes thicker or thinner, altering its refractive power accordingly.

While it may seem tempting to consider the crystalline lens's function as dependent on specific conditions or age, the fundamental characteristic of the lens being refractive remains true. Thus, stating that the crystalline lens is non-refractive does not accurately reflect its physiological role in vision.