Early 20's - options to Improve dark under eye circles? (Photos)

Hello - My best recommendation at this time is to start a good skin care regimen. This and botox are the cornerstones of prevention early on (as well as sunscreen). A good skin care regimen consists of a cleanser, moisturizer, and an exfoliant at least twice a week. You want to also add a hyaluronic acid to plump up your skin as well.
In addition to this, I would begin regular facials and a micro needling regimen. A facial will allow your skin to stay plump and and a micro needling regimen will begin stimulating collagen. After age 18 we lose about 1% of our collagen a year, so this is important.
The darkness under our eyes usually comes from the skin becoming thin and allowing the muscle to show through the skin.

Based on your photos, you appear to have thin white skin, and "allergic shiners." Unfortunately, there are no topical or other non-invasive treatments that I'm aware of to prescribe. Thank you for you question. Sincerely, Dr. Joseph