Introduction: Recent years have seen a growing interest in the periocular region, with a consequent increase in the number of treatments performed in this area and the appearance of hyaluronic acid fillers designed for this anatomical area. The injection of hyaluronic acid (HA) fillers into the tear trough is a minimally invasive and quick to perform practice, but it is one of the most challenging non-invasive aesthetic procedures to perform, both because of the possible adverse effects of HA injection and the anatomical complexity of the area to be treated. Good results require a good anatomical knowledge of the tear duct, a proper clinical assessment of the patient and the use of an appropriate injection technique with the right product. Objectives: The aim of this scientific paper is to illustrate how to improve the patient's aesthetic appearance by treating the deformity of the eye canal. Several factors contribute to the hollowed appearance of the eyeball and the appearance of a shadow on the lower eyelid, including thinning and drooping facial fat pads. Treatment means correcting the change in volume, but also correcting the position of the deep fat compartments, depending on the aetiology of the deformity. In all cases, careful evaluation and patient selection are essential. Materials and methods: Due to the special characteristics of this area, a soft, low-hygroscopic HA filler with adequate cohesiveness and low viscosity, designed specifically for the treatment of the periocular area, was identified as the ideal filler. The point at which the projection line of the nasojugal fold converges with the line perpendicular to the outer corner of the eye was identified as the entry point. To minimise trauma, given the anatomical complexity of the treated area, the use of the microcannula (25G or 27G) was preferred over the needle. The injection was performed in a deep, supra-periosteal plane in order to prevent any adverse events such as compression of the lymphatic vessels (located on the surface) or the Tyndall effect. The injection was carried out using a linear retrograde technique mixed with microbolus and a maximum amount of filler of 0.5 ml per side was injected. Results: The satisfaction rate with this method is high; overall, all patients experienced a general aesthetic improvement with a single session. In some cases it was necessary a retouch with a second vial. The retouch with a second vial is not recommended earlier than 4 weeks after the first session. In summary, this technique and this type of filler are safe, with a high degree of satisfaction and a low complication rate. Conclusions: Tear trough treatment using a microcannula and a HA filler, is safe, painless and free of major complications. Compared to needle tear trough treatment, this technique statistically reports a significantly lower rate of bruising and complications. Although there are common side effects such as local post-treatment swelling, these are temporary and resolve completely within a short time. The patient satisfaction rate is very high, the improvement is immediately perceptible and long-lasting. Bibliography: Lemaire, T. Région infraorbitaire, anatomie et dangers, in Anatomie et injections volumatrices. E2e Medical Publishing, Master Collection 2, Paris. 2011. p23-64.