The stratum lucidum is a thin, clear layer of dead skin cells found primarily in the thick skin of the palms of the hands and the soles of the feet. Its main function is to provide an additional protective layer that improves the skin’s resistance to abrasion and friction. This layer is composed of flattened, densely packed keratinocytes that are filled with a protein called eleidin, which gives it a translucent appearance.
One of the key roles of the stratum lucidum is to act as a barrier to moisture loss, which helps to maintain hydration levels in the underlying layers of the skin. By aiding in the overall structure of the epidermis, this layer enhances the skin’s durability and flexibility, allowing it to withstand the physical stresses encountered in areas subject to heavy use.