23 y/o male, what are these lines around my eyes and how do I flatten them? photos)

For unique cases where a variety of modalities could be used to treat the condition, I would suggest an in-person or virtual consultation to develop a custom and effective treatment plan. It is difficult to precisely define the best option without collecting the same information. I suggest reaching out to an expert for a consultation with surgical and non-surgical methods to get a comprehensive option. Best, Dr. Emer.

Weight gain and loss can impact the contours of the face. You may want to explore Morpheus8. These treatments combine RF technology with microneedling to improve overall skin tone and texture. I've included a video that I hope you find helpful.

Lines around the eyes can start forming in our late 20s. Under the eyes in the tear trough area it is caused by volume loss which can be replenished with hyaluronic fillers. This is particularly common in young men that don't have cheeky bone structure. On the side of the eyes it's caused by muscle movement of the lateral obicularis, commonly called craw's feet. These lines can be undone with botulinum treatment like Botox, Dysport, Daxxify, Jeuveau or Xeomin.
What you're seeing is all normal.