Brown splotches on the forehead or cheekbones may be due to a skin condition known as hyperpigmentation, which indicates that certain areas of the skin produce more melanin, in dark spots. The easiest way to improve the situation is to use skincare products with vitamin C and avoid sun exposure. Still, patients need to understand that it does take a little time. The use of sunscreen can help prevent the spots from getting darker. You can visit a dermatologist in case of failure.