Sunken eyes and reduced skin firmness can be related to ageing, stress, or lack of proper nutrition and sleep. You can try simple facial exercises like gentle under-eye tapping, eye tightening and relaxation, and cheek lifting to improve muscle tone and blood flow. Staying well hydrated, eating a balanced diet, and getting enough sleep are equally important for better skin health. If the concern persists or worsens, consider consulting a doctor or skin specialist for proper guidance.