What does the term "canthus" refer to in anatomy?

The term "canthus" refers specifically to the angle at either end of the eyelid slit, which is the point where the upper and lower eyelids meet. This anatomical term is used in ophthalmology and related fields to discuss various aspects of eye health, including the assessment of eye conditions and surgical procedures. The canthus is important in understanding normal eye anatomy as well as in diagnosing and treating certain ocular disorders.

The other terms mentioned do not accurately describe the canthus. The fold of skin covering the eye refers to the eyelids themselves, whereas the inner ear structure pertains to auditory anatomy, and the outer layer of the cornea describes a part of the eye but is unrelated to the angles formed by the eyelids. Thus, recognizing the definition and context of "canthus" is crucial for clear anatomical communication.