An arcus is an abnormal condition in which the eyelashes grow in the direction of the eyeball so that they touch the eye. It is a common external eye disease in children, adolescents and the elderly, and is mainly caused by abnormal growth of the eyelashes. Eyelashes that grow in an abnormal direction, especially those that grow backwards toward the corneal surface, often rub against the corneal epithelium, causing symptoms such as foreign body sensation, photophobia and tearing, as well as causing eye congestion, conjunctivitis, corneal epithelial detachment, keratitis, corneal vascular opacity, corneal ulcers and corneal white spots, which can affect vision. Double eyelid surgery does not usually result in impingement. On the contrary, the upper eyelid with entropion-type impingement can be treated by double eyelid surgery. It solves the problem of upper eyelid ingrown eyelashes while obtaining a beautiful pair of eyes with double eyelids. Will double eyelids be fake afterwards? Since the double eyelids are formed artificially afterwards, it is completely understandable that the shape is a bit fake. It is also understandable that some people’s eyelids may look fake due to their own conditions. However, most of the double eyelids can get more natural and harmonious results after good doctor-patient communication, elaborate pre-operative design and fine surgical operation, especially after a longer recovery time. In the specific operation, the pre-operative design should be integrated with all factors of the candidate, and the personalized double eyelid shape should be designed according to the eye shape, facial features ratio and overall temperament of the candidate. At the same time, the operator needs a clear understanding of eye anatomy and fine operation, which is a prerequisite to ensure that the double eyelid surgery looks natural afterwards. In addition to the surgeon, it is important for the patient to avoid excessive and unrealistic expectations, such as requiring a certain celebrity eye shape or an overly wide eyelid width, which can lead to a “fake” look after surgery.