These also help to conceal your eyelids and make them look more even.
This post is dedicated to Nyx Eyeshadow base in the shade Skin Tone. It also comes in Pearl and White.
To show you how it works I used a MUA eyeshadow in shade 19(which I use for my brows) without a base(left) and with Nyx Eyeshadow base(right)
I don't know how else can I convince you that this really works.