Photoaging

One key factor of aging is sun light that can cause heterogeneous pigmentation, damage to the skin collagen and vasculature, and eventually premature aging. UV radiation can penetrate the middle layer of skin, namely dermis, causing an abnormal buildup of elastin. Enzymes are then produced against elastin which also break down collagen leading to solar scars, sagging, uneven thickening and thinning of face known as solar elastosis and yellow discoloration.
Freckles are the most common sun-induced pigmentation disorder due to the damage to the melanocytes that produce skin’s color pigments. Age spots are indeed larger freckles that typically appear in older adults on the back of hand, shoulders, arm and upper back. UV radiation from sun plays role in facial vascular disorders such as bruising and spider veining telangiectasias as it can cause thinning of blood vessel walls. UV radiation is also one major creator of free radicals blamed for molecular damage to the cells. Free radicals are unstable oxygen molecules that lack one electron to become stable form with aired electrons. By taking the missing electron from other molecules they can cause damage to the cell’s genetic material.