Pores are essential to your skin's health by providing oil to keep skin soft and hydrated. However, you don't necessarily want to be reminded of their existence every time you look in the mirror. Pores are more prominent when they are dilated, infected, or clogged with oil, making them appear larger than they really are. While it isn't possible to permanently "shrink" large pores, there are a number of ways to make them less noticeable. Cause of Large Pores: There are two main factors that contribute to large pores: genetics and age. People who have skin that is naturally thick and oily tend to have larger pores. As people get older, too, sun damage and decreased skin elasticity can cause pores to dilate. The skin thickens, causing tiny cells to collect around the edge of the pores and make them look larger. Blackheads are also a big contributor to large pores. When the pore becomes clogged by dirt and bacteria, oil within the pore begins to accumulate, causing the pore's diameter to expand.