Why does sunscreen have nanoparticles?

Sunscreen contains nanoparticles, such as zinc oxide or titanium dioxide, to enhance its effectiveness while minimizing visible residue on the skin. These tiny particles provide broad-spectrum UV protection by reflecting and scattering harmful UV rays. Their small size allows for a lightweight and non-greasy texture, making the product more cosmetically appealing and easier to apply. Additionally, nanoparticles can improve the stability and longevity of the sunscreen formulation.