Which part of the eye is a tough white layer connected to six muscles?

The sclera is the tough white layer of the eye that provides structural support and protection. It serves as the outermost layer of the eyeball and is made of dense connective tissue, which is why it is both tough and resilient. Additionally, the sclera connects to six muscles that are responsible for controlling eye movement. These muscles allow the eye to move in different directions, enabling visual tracking and coordination with head movements.

In contrast, the lens is a transparent structure that focuses light onto the retina, while the cornea is the clear, front part of the eye that also helps with focusing light but does not connect to muscles. The retina, on the other hand, is the inner layer of the eye that contains the photoreceptors for sight. Therefore, the sclera is uniquely identified by its toughness, color, and role in muscle attachment, making it the correct answer.