Betel (Piper betle) leaves have a long history of use in traditional medicine systems across South and Southeast Asia. One traditional application involves using extracts, decoctions, or infusions of betel leaves as eye washes or poultices to address eye infections or irritation. The rationale for this practice stems from betel leaf's reputed antimicrobial and anti-inflammatory properties, as described in ethnobotanical records and Ayurvedic texts. Betel leaves contain a variety of phytochemicals, including eugenol, chavicol, and other phenolic compounds, which have demonstrated general antimicrobial activity in laboratory studies.

However, direct scientific evidence supporting the efficacy and safety of betel leaf specifically for treating eye infections in humans is minimal. Most available studies focus on the antimicrobial action of betel leaf extracts against common pathogens in vitro, rather than on actual ophthalmic applications. There are no substantial clinical trials or robust animal studies that confirm its effectiveness or safety for eye conditions. Therefore, while the use of betel leaf for eye infections is justified by tradition and historical practice, scientific validation remains lacking. The evidence rating is 1, reflecting anecdotal and traditional support but an absence of rigorous scientific data.