What is the main component of the fibrous tunic of the eye?

The main component of the fibrous tunic of the eye consists of the cornea and the sclera. The fibrous tunic, also referred to as the outer layer of the eye, primarily serves to provide structural support and maintain the shape of the eyeball. The sclera is the white part of the eye, which is a tough, protective outer layer. It is continuous with the cornea, the clear front part of the eye that allows light to enter and helps in focusing images onto the retina. Together, these two components form the fibrous tunic and play a crucial role in protecting the inner structures of the eye while also helping to maintain optical integrity.

Other choices include components like the ciliary body and the iris, which are part of the middle layer of the eye (vascular tunic), as well as the retina, which is part of the innermost layer (neural tunic) responsible for processing visual information. These structures, while important in their functions, do not comprise the fibrous tunic.