What term describes the clear outer anterior part of the eye's focusing system located at the front of the eye?

The term that describes the clear outer anterior part of the eye's focusing system located at the front of the eye is the cornea. The cornea plays a crucial role in refracting light that enters the eye, helping to focus images on the retina. Its transparent structure allows light to pass through while still providing protection to the inner components of the eye.

In contrast, the iris is the colored part of the eye that controls the size of the pupil and the amount of light that enters the eye; it does not participate directly in focusing light. The lens is situated behind the iris and helps in focusing light further, but it is not the outermost layer. The sclera is the white, fibrous outer layer of the eye that provides structure and protection but does not have the clarity required for light refraction. Thus, the cornea is specifically identified as the clear outer part of the eye essential for proper vision.