“…9,10 However, 254 nm UVC can deeply penetrate human tissues and lead to severe diseases such as skin cancer and keratitis, limiting its application to no-human zones only. 11,12 Different from UVC at 254 nm, far-UVC at 222 nm has a transmittance of #1% in keratin and corneal, given that light can be effectively absorbed by proteinaceous matter. [13][14][15][16][17][18] Thus, it may not penetrate the stratum corneum of human skin and the cornea of the human eye, protecting humans from UV-induced diseases.…”