A highly hydrophilic coating with a water contact angle below 10° was developed on a transparent polycarbonate (PC) sheet using a UV-curable process. Polyhedral oligomeric silsesquioxanes (POSS), modified with poly(ethylene glycol) methacrylate (PEGMA), provided the hydrophilic functionality essential for the coating. Fogging and frost formation on transparent surfaces often hinder visibility and pose challenges in various optical applications. The hydrophilic coating developed in this study demonstrated excellent antifogging and antifrost properties, along with a notable self-cleaning capability. These characteristics make it a promising candidate for applications in transparent optical PC materials, requiring enhanced antifogging, antifrost, and self-cleaning performance.