Detailed answer

Heredity, or genetics, contributes to the presence of dark circles and under-eye bags to a considerable extent. Factors such as the thickness of the skin, underlying fat distribution, and bone structure around the eyes are genetically determined. Some individuals may inherit thinner skin that makes the blood vessels underneath more visible, leading to the appearance of dark circles. Others may have a genetic predisposition to have more prominent fat pads under the eyes, resulting in under-eye bags. While heredity is a major contributor, other factors such as aging, lack of sleep, allergies, and lifestyle choices can also influence the development of dark circles and under-eye bags.