Overview of Non-Invasive Blood Glucose Monitoring Techniques: Focus on Optical Methods Kholoud Fdil, Safae Elhir, Ikram Debbarh and Hicham Medromi E3S Web Conf., 631 (2025) 02007 Published online: 26 May 2025 DOI: 10.1051/e3sconf/202563102007