Each patient is different, but in general, the dark circles under the eyes are caused by a shadow effect due to the lower lid tissue above the tear trough, a deep tear trough, a medical issue such as allergies, thin skin, or just purely genetics. Only a history and physical exam with a well-trained surgeon can help to identify the treatment for each individual. In general, I often recommend non-surgical treatments in younger patients, and surgical treatments in older patients, but each patient is unique. Surgery can help to decreased the bulge of the lower eyelid that may be causing any shadow and can also help to reposition fat in order to fill in the tear trough. Fillers can help to disguise the tear trough and smooth any irregularities that may be causing a deep trough or contributing to the shadow effect, but fillers are temporary, and can sometimes make the dark color worse or appear somewhat blue in color. Treatment of allergies that may be causing dilation of the blood vessels around the nose and eyes can also be helpful if indicated. As always, a detailed history and physical exam with an experienced surgeon is needed to determine treatment recommendations. Be sure to see an expert surgeon who specializes in facial aesthetic procedures. All the best,