Our eyes do not just help us see. They are also the idiomatic windows to the soul, capturing people’s attention, as well as boosting our self-esteem.
Dr Lam Bee Lan is the medical director of Ageless Medical Centre. She answered questions from DoctorxDentist readers regarding under eye and tear trough hollowing, and fillers in the eye area. Here's what she had to share.
What causes sunken-looking undereyes?
Dr Lam noted that sunken, depressed undereye areas with severe pigmentation can cause dark eye circles.
Because the skin around the eyes is delicate and thin, it is more susceptible to signs of ageing. Fine lines, wrinkles, and visible volume loss are just some of the symptoms of ageing. 
Genetics, health, and lifestyle habits are also factors
Many cases of sunken upper eyelids are related to an individual's genetics, health, and lifestyle habits as well as age. Either way, some people think sunken upper eyelids create an aged and tired look. 
Stress on the eyes can compromise skin health
When we strain our eyes for prolonged periods, such as when we stare at the computer or mobile devices, the immunity and health of the skin that surrounds the eyes can be compromised.
This can lead to a sunken and depressed look in the upper eye area. 
Some post-eyelid surgeries can cause the condition
Without available techniques and technology, blepharoplasty procedures were not as advanced as they are now. As a result, sunken eyelids were common side effects experienced by many patients. 
Filler injections can help restore skin volume
A common treatment for sunken undereye areas is hyaluronic acid filler injections, which would be applied in small amounts by an experienced aesthetic doctor. Essentially, this can help replace the volume loss that occurs in the upper eyelid skin to produce a natural and refreshed look.
When it comes to applying fillers around the eye area, a trained doctor with plenty of experience is necessary if you want safe and natural-looking results.
The application of fillers is determined on a case-by-case basis. Sometimes, a patient will need more than one filler, although it generally only takes one session to treat dark circles. The severity of the sunken look may also be taken into consideration. Alternatively, fat grafting can be performed, but this surgical technique requires an experienced plastic surgeon. 
How long does it take for fillers in the eye area to work?
The results for fillers are typically instantly visible. As the fillers gradually integrate with the skin tissues, the visible results will improve over time. Fillers last between 6-9 months and can last longer with repeated treatments. 
Ultimately, upper and lower sunken eyelids are caused by various factors that are determined on a case-to-case basis. However, there are multiple treatment options that are effective and safe. Be sure to consult your doctor before opting for any of these solutions.
1. Shetty R. Under eye infraorbital injection technique: The best value in facial rejuvenation. Journal of Cosmetic Dermatology. 2014;13(1):79-84. doi:10.1111/jocd.12075 https://onlinelibrary.wiley.com/doi/abs/10.1111/jocd.12075
5. Karol A. Gutowski. "Hyaluronic Acid Fillers: Science and Clinical Uses." Minimally Invasive Rejuvenation of the Face and Neck, An Issue of Clinics in Plastic Surgery. Published 2016. Accessed April 11, 2019.
6. Monheit GD, Coleman KM. Hyaluronic acid fillers. Dermatologic Therapy. 2006;19(3):141-150. doi:10.1111/j.1529-8019.2006.00068.x https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1529-8019.2006.00068.x