Those slight indents under the eyes are often related to the tear trough, where the natural transition between the lower eyelid and cheek creates a shadow. Genetics, skin thickness, collagen loss, and changes in facial volume can all make this area more noticeable. Retinol can help over time by improving collagen production and skin texture, while caffeine may temporarily reduce puffiness and make the area look a little smoother. However, neither will actually replace lost volume, so the improvement may be limited if the indentation is primarily structural. Since you don't want under-eye filler, there are several other options to consider: RF microneedling: Can stimulate collagen and tighten the skin, which may soften fine lines and improve the overall texture of the under-eye area. Fractional laser resurfacing: Depending on your skin type and the specific laser used, this can improve fine lines, texture, and collagen production. It needs to be performed carefully around the eyes. PRP/PRF: These treatments use your own blood-derived growth factors and may gradually improve skin thickness and texture. Results tend to be subtle and develop over several treatments. Collagen-stimulating injectables: Certain biostimulatory treatments can improve skin quality and support collagen production without directly filling the tear trough. These require careful product selection and placement around the eyes. Lower eyelid surgery (blepharoplasty): If there is significant hollowing, fat displacement, or skin laxity, a surgical approach can address the underlying anatomy rather than simply adding volume. One important point is that under-eye “lines” and hollowness aren't always the same thing. If the indentation is caused primarily by the natural anatomy of the tear trough, topical products can improve the quality of the skin, but they generally won't completely eliminate the hollow itself. Also, I would avoid aggressively applying strong retinoids directly too close to the lash line because the skin in this area is very thin and easily irritated. A gentle formulation used carefully can be a better approach.