As modern information systems grow in complexity, users increasingly face cognitive challenges that hinder performance, comprehension, and decision-making. Cognitive Load Theory (CLT), originally developed for instructional design, provides a powerful lens for understanding how interface design can optimize human cognitive resources. This research explores how CLT principles apply to complex IT interfaces such as enterprise dashboards, cloud platforms, cybersecurity consoles, and decision-support systems. The findings show that intrinsic, extraneous, and germane cognitive loads must be carefully managed to improve usability, efficiency, and user experience. A Cognitive Load–Optimized Interface (CLOI) framework is proposed to guide interface designers in reducing overload, enhancing comprehension, and supporting expert decision workflows. Implications for UX design, enterprise IT architecture, and human-centered computing research are discussed.