It feels flat, so I want to get fillers.

I've been told that I look tired because of the visible lines or flatness under my eyes when I smile or just stay still, so it's been subtly bothering me about my appearance every time I look in the mirror. I don't really want to go as far as fat repositioning surgery because the recovery period is long and I'm not keen on the procedure itself, so I'm planning to go with under-eye fillers or skin boosters, which seem relatively simpler. However, since the skin under the eyes is so thin and blood vessels show through easily, I'm really worried that it might look bluish due to the Tyndall effect or clump up and wobble.

When the volume is naturally filled into the sunken area under the eyes, does the base of the under-eye area tend to be filled in smoothly without any unevenness?

I am curious to hear the opinions of those who have already undergone the procedure, such as how many days it takes for bruising or slight swelling around the eyes to subside after the injection, or whether it would be better to reinforce the thin skin thickness first using an under-eye skin booster instead of fillers.