It is unusual for a 20-year-old to have loose skin. Loose skin is an age-related change. It can be present in younger people if there is a lot of eye rubbing, allergies, sinus problems, skin issues and other problems that can accelerate the skin into getting thinner. I also noticed in your photos that you have an area of puffiness under your eyes. Based on those photos, I think you have something called lower eyelid fat prolapse.
If you notice that your eyes are puffy on pretty regular basis then this is caused by fat behind the eyelid that pushes forward. The most common factor responsible for this is genetics. If there are other factors such as sinuses and allergies, it tends to make the fat pockets a little more swollen. If this is also associated with eye rubbing then it can make the skin thinner.
In my practice, we do a step by step evaluation of the elements that can make the eyes look like they’re tired and addressing the wrinkles is part of that evaluation. At 20 years old, this is the time of your life when your skin is going to be at its best. You may want to consider some minimal intervention such as the use of topical creams and moisturizers to help protect your skin. You also may want to see a specialist to get an evaluation why the skin is thin. Your darker skin type tends to hold very well unless there are environmental allergies and other factors.
To summarize my perception of your skin issue, you may want to be conservative about any topical treatment for the wrinkles. In our practice, we actually have a skin care line and one of our popular products is the Eye Rescue cream. It’s a combination of moisturizers and some active ingredients that’s well tolerated by our patients. There are also a lot of eye creams in the market that you may want try first. Eye cream is one of the key elements of helping skin that appears wrinkled. Also, take a look at your eyes in the morning and compare them in the evening. See if it tends to be puffy more often than not. If it does, then you may want to consider some type of aesthetic procedure. 20 is a little young for such a problem, but with modern technology and techniques it’s something that can be addressed. I hope that was helpful, and thank you for your question.