canthus

anatomy

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June 22, 2026

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The term "canthus" refers to the angles formed where the upper and lower eyelids meet. There are two canthi: the inner canthus, located closest to the nose, and the outer canthus. These points define the almond-shaped opening of the eye, known as the palpebral aperture. The eyelids themselves are composed of four layers: skin, muscle, a fibrous layer for stability, and the conjunctiva, a mucous membrane that attaches the eyeball to the orbit and lids. In reptiles and amphibians, the term "canthus rostralis" describes a ridge extending from the eye's edge to the nostril. The combining form "canth-" is used in anatomical terms related to the canthus.1234

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human eye
The eyelids
…the nose is the inner canthus, and the other is the outer canthus. The lid may be divided into four layers: (1) the skin, containing glands that open onto the surface of the lid margin, and the eyelashes; (2) a muscular layer containing principally the orbicularis oculi muscle, responsible for…
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…the nose is the inner canthus, and the other is the outer canthus. The lid may be divided into four layers: (1) the skin, containing glands that open onto the surface of the lid margin, and the eyelashes; (2) a muscular layer containing principally the orbicularis oculi muscle, responsible for…
Read More