There can be a number of reasons for the development of dull / dry skin.
As a person ages, the skin naturally starts to produce less oil. The complexion starts to look less radiant as dead skin cells start to build up on the face.

The skin can also start to lack in hyaluronic acid which helps to maintain adequate moisture levels, and the skin begins to dry out. Drinking plenty of water and eating a healthy diet can contribute to brighter looking skin that stays well hydrated. Lifestyle habits, such as smoking and consuming alcohol, can also cause dehydrated skin. This contributes to a dull complexion, as well as leading to changes in pores size and texture.
Regular cleansing and exfoliation is key to eradicating dead skin cells and retaining essential moisture levels. A treatment that works to help with this process can enhance the overall appearance and condition of the skin for a youthful and vibrant look.