Ive found that can settle in lines and creases if you don't hydrate well under the eyes first. I use a full skincare routine including an under eye primer before concealer. I think it also has to do with the quality & type of concealer you use first. It is a great product when used carefully. It does brighten the under eye, not dramatically but just enough. It's a very fine silky-smooth powder. I don't feel it's absolutely necessary but prefer it. I recommend at least trying it.

This is an ultra translucent, weightless, loose, setting powder that sets make up for extended wear. This gives your make up a smooth, silky, and invisible finish. It helps to smooth and blur the look of fine lines and imperfections. This milled powder sets your make up so nicely, and a little bit goes a long way. This is my favorite powder for setting my under eyes. Totally recommend this powder! 

I really love this stuff. Usually powders under my eyes are horrible no matter how expensive. They sink into my under eye lines and show lines I didn't even know existed. This stuff doesn't do that at all. It truly smooths the under eye area no matter how tired or aged I am or look that day. It also brightens extremely well. I also noticed that because of it's super fine particles and brightening and blurring qualities it is absolutely amazing for the entire face. Especially to blur pores and brighten the skin in a natural looking way. I know the pot looks small but its so good a little really does go a long way. Totally recommend. Received complimentary for testing purposes.