The Sun. Those brown spots on your nose come from being out in the sun unprotected too long. As we age our skin is subjected to more and more sun damage. Our skin has melanin pigment which absorbs sunlight and helps naturally protect our skin from UV rays. However as we age, our skin's natural ability to fend off UV rays from the sun begins to deteriorate, and we see the development of age spots. Age spots can be effectively treated with lasers.

For more information see: How Can I Remove Age Spots?, Laser Treatment for Age Spots, & Choosing a Doctor