Zayn: The way they crinkle up when he laughs or smiles too wide. First you see his amber brown eyes, then you don't and it's absolutely adorable. The way they sparkle in the light is absolutely gorgeous and you tell him many times that they're your favorite thing to look at.
Liam: The most amazing, heartwarming shade of brown. Nothing makes you happier than seeing his eyes twinkle when he smiles, or even cuter-- his sleepy eyes. No matter where you two are, nothing can capture your attention more than when he makes eye contact with you, his smile lighting up his entire face, making his eyes form into those tiny crescents you just adore.
Louis: They're perfect, the perfect shade of blue, just enough to make your stomach fill with butterflies once they meet yours. His eyes are the perfect example of being "the windows to your soul." Whenever he's happy, angry, heartbroken or even excited, his eyes give it up right away. The way they brighten up your mood is ridiculous and you couldn't ask for anything better.
Harry: You've never seen eyes that were the most incredible shade of green, but he fulfilled that for you. His tired eyes, his happy eyes, his sad eyes, his puppy dog eyes-- all of them just making you melt with giggles. But for some reason, when Harry drinks just a bit too much, those beautiful eyes gloss over and droop a bit, and they turn you on a whole lot.
Niall: Everyone knows that they're the most amazing things you can ever set your own eyes on. A beautiful blue with yellow speckles just around his pupil. They tell a story and he doesn't even know. They give away his deepest thoughts and feelings, only those that you can recognize. But the one story they tell that you can never get enough of is when he looks at you, the way they stare down at you, wide and happy, full of love and cherish, like you're his most prized possession, and little do you know, you are.