The use of Cicada (specifically, the slough or exuviae of Cicadae periostracum, known as "Chan Tui" in Traditional Chinese Medicine) to support or treat eye infections is rooted primarily in traditional medicine practices rather than scientific validation. In the context of Traditional Chinese Medicine (TCM), Chan Tui is described as having properties that "dispel wind-heat," "clear the eyes," and "remove superficial visual obstruction." Historically, it has been included in TCM formulas intended to treat conditions such as redness, swelling, and itching of the eyes, and sometimes for superficial visual disturbances believed to be caused by wind-heat pathogens.

However, scientific research directly evaluating the efficacy or mechanisms of Cicada slough for eye infections is extremely limited. Modern pharmacological studies have focused more on its potential anti-inflammatory and antipyretic effects in animal models, but there is a lack of robust, high-quality clinical trials in humans addressing eye infections specifically. Thus, while its use is well established in traditional herbal medicine texts and among practitioners of TCM, the current scientific evidence supporting its effectiveness for eye infections is minimal to nonexistent.

In summary, the justification for using Cicada to treat or support eye infections is based on traditional use in Chinese medicine, with little direct scientific evidence available to confirm its efficacy for this indication.