Which location is the "eye head"?
Feb 08, 2023
Source: Cainiu Health
Dr. Cui Xin
Introduction
The medial canthus generally refers to the inner corner of the eye, where the upper and lower eyelids meet medially. In contrast, the lateral canthus is the point where the upper and lower eyelids meet laterally. The medial canthus has a blunt, slightly horseshoe-like shape. Between the medial canthus and the eyeball lies a small curved area known as the lacrimal lake. Additional anatomical structures are also present at the medial canthus, such as the caruncle and the plica semilunaris.
The medial canthus generally refers to the inner corner of the eye, where the upper and lower eyelids meet on the nasal side. In contrast, the lateral canthus is the point where the upper and lower eyelids meet on the outer side.
The medial canthus has a blunt, rounded shape, somewhat resembling a horseshoe. Between the medial canthus and the eyeball lies a small, curved depression known as the lacrimal lake. Additional anatomical structures are present at the medial canthus, such as the caruncle and the semilunar fold of conjunctiva. The integrity of these structures ensures complete eyelid closure and facilitates the natural drainage of tears into the nasal cavity. At the junction of the upper and lower eyelids in the medial canthus, there is a small opening called the lacrimal punctum, which serves as the entrance to the tear drainage system. Therefore, the medial canthus plays a crucial role in eye function. Injury to this area may lead to eye deformity, reduced palpebral fissure size, and alterations in the tear ducts, resulting in excessive tearing. Due to excess skin and fat covering the medial canthus, the eyes may appear rounder and less defined, affecting aesthetic appearance. Clinically, during double eyelid surgery, an epicanthoplasty (medial canthoplasty) is often performed to enlarge the inner corner of the eye.
If inflammation occurs in the medial canthus regularly, it's important to consider whether prolonged eye use—such as extended screen time from computers or televisions—is causing dryness or eye fatigue, which are common contributors today. Additionally, exposure to cosmetics that come into contact with the eyes may also be a contributing factor.
