This thesis investigates the optical properties of tendons in both perpendicular and parallel to their fiber direction, important for applications like Photobiomodulation Therapy (PBMT). Commonly, tissues are treated as optically homogeneous mediums with a single set of optical parameters regardless of the direction in which light travels through the tissue. This simplification falls short for highly anisotropic tissues like tendons, which may be more scattering in one axis than the other. The goals of this thesis are to characterize the optical properties of tendons for light propagating perpendicular to the tendon fibers, and for light propagating parallel to the fibers. Longitudinal and transverse sections of tendon were studied, respectively. This includes an examination of scattering, anisotropy, and the influence of light guiding. The thesis also investigates the effects of an optical clearing agent, glycerol, on tendon optical properties at two concentrations — 10% glycerol, a concentration safe for therapeutic injections, and a much higher concentration of 60%, on enhancing light propagation in tendons. Key findings indicate that at 808 nm, a clinically relevant wavelength, longitudinal tendon sections exhibit significantly higher scattering intensity compared to transverse sections, with more than a tenfold increase in reduced scattering coefficients (6.7 mm⁻¹ longitudinally vs. 0.52 mm⁻¹ transversely). The immersion of samples in 60% glycerol improves the forward direction of scatter and increases transmission, effects that are less pronounced with 10% glycerol. Lastly, the scattering properties of tendons, both transverse and longitudinal, decrease with increasing wavelength, displaying characteristics of both Mie and Rayleigh scattering. These findings reveal that tendon, one of the most anisotropic connective tissues, has extremely anisotropic optical properties that favor optical propagation along the axis of the tendon.