For anyone who loves wearing eye makeup, you’ve probably faced the frustrating midday meltdown: your once-vibrant eyeshadow starts creasing in the eyelid fold, your eyeliner smudges onto your lower lash line, or your carefully blended look fades into a dull mess. If this sounds familiar, you’re missing a game-changing step in your routine: eye primer. But what exactly does an eye primer do, and why is it non-negotiable for long-lasting, professional-looking eye makeup? Let’s break down its key functions, benefits, and how it transforms your eye makeup game.