First, The most common reason is to It protect your Skin from UV Rays. The depletion of the ozone layer has increased our risk of sun damage from harmful UV rays. Next, by applying sunscreen each day, you cut your risk of contracting skin cancers in half. Sunscreen also helps prevent discoloration and dark spots from sun damage, helping you maintain a smoother and more even skin tone. Lastly, It Prevents Premature Aging of the Skin. Sun damage from UV rays causes photoaging of the skin thus making it look tired or unappealing. So please help yourself to prevent this. Stay safe!