What is the term for a clear covering lining the outer surface of the eyeball?

The term for the clear covering lining the outer surface of the eyeball is the conjunctiva. This thin, transparent membrane plays a crucial role in the eye's anatomy by covering the anterior part of the sclera (the white of the eye) and the inner surfaces of the eyelids. Its primary function is to protect the eye and keep it moist by producing mucus and tears.

In contrast, the cornea is the clear, dome-shaped surface that covers the front of the eye but is not the same as the conjunctiva. The sclera is the tough, protective outer layer of the eye that provides structure and support but does not have the properties of being a clear covering. The retina, located at the back of the eye, is vital for vision as it contains the light-sensitive cells that convert light into neural signals but does not serve as an outer covering of the eyeball. Thus, the conjunctiva is the correct term as it specifically denotes the outer lining that is clear and protective.