What does canthus mean?
The canthus is the corner of the eye — the point at which the upper and lower eyelids meet. Anatomists distinguish two on each eye: the lateral (or outer) canthus, toward the temple, and the medial (or inner) canthus, toward the nose, where tears drain into the nasolacrimal system. The word derives ultimately from the Greek kanthos, meaning the corner of the eye, and entered English via Latin in anatomical usage around the seventeenth century. It belongs firmly to the vocabulary of medicine: ophthalmologists, oculoplastic surgeons, and anatomists use it with precision, while general writers rarely need it beyond describing the eye's structure. Related terms include canthal (adjectival), epicanthus (a skin fold covering the inner canthus, common in people of East Asian ancestry), and the plural canthi. Though unfamiliar to most lay readers, it is indispensable in clinical description and surgical planning.
nounThe corner or angle where the upper and lower eyelids meet, at either the outer or inner side of the eye.
- Either corner of the eye where the upper and lower eyelids meet; specifically distinguished as the lateral (outer) and medial (inner) canthus.
"A fine network of wrinkles radiated from the outer canthus of her eyes."
"Tears collect at the inner canthus before draining through the nasolacrimal duct."
"The surgeon placed the incision precisely within the lateral canthus to minimise visible scarring."
The standard plural follows the Latin form 'canthi'; 'canthuses' is an acceptable anglicised variant but less common in clinical writing.
"Both lateral canthi were examined for signs of laxity."
The little word for your eye's corners comes straight from Greek — and it's why the 'Asian eyelid fold' is formally called the epicanthus.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of canthus
Canthus comes from the Latin canthus, itself borrowed from the ancient Greek kanthos (κάνθος), meaning the corner of the eye. The term entered English anatomical vocabulary in the early modern period, by the seventeenth century, as classical learning shaped medical nomenclature. It shares this Greek root with related anatomical derivatives such as canthal and epicanthus, the latter denoting the skin fold over the inner corner of the eye.
Related word forms
How canthus is actually used
Canthus is a technical term used chiefly in anatomy, ophthalmology, plastic surgery, and medical writing. In everyday speech people simply say 'the corner of the eye'. The plural is usually given in its Latin form 'canthi', though 'canthuses' also occurs.
Easily confused with canthus
"Cantus" is a musical term meaning a melody or chant, whereas "canthus" is the anatomical corner of the eye.