It takes Jaskier a while to notice it, but eventually he realises Geralt‘s eyes aren’t all they seem. He can pass them off as human eyes, albeit an unusual amber colour, but it requires that he concentrate to keep his pupils a regular round shape.
When he’s focused on something else, or when he’s very tired, his pupils slip into cat-like slits, a tiny sliver of black running vertically through the amber. Jaskier thinks it’s the most beautiful thing he’s ever seen, not that he mentions that to Geralt.
When Geralt is on a hunt in a dark forest, his pupils swell out into plump slits that let him see in the dark but maintain peripheral vision, helping him dodge nimbly out of the way of dangerous swipes from vicious monsters. Geralt is elegant and deadly, and Jaskier will never tire of watching his graceful form dance through combat.
It’s not just those three shapes though. After several months, Jaskier notices a new shape, one he struggles to place. Sometimes he’ll be performing in a tavern and glance over to Geralt, or they’ll be sitting around the fire and he’ll be humming a tune, and when he looks up Geralt’s pupils have ballooned into fat, round orbs, almost eclipsing the irises completely. It doesn’t happen often, and rarely in company. It seems to happen most frequently when it’s just the two of them, somewhere quiet and peaceful.
Geralt looks almost comical like that, almost… well, Jaskier would say adorable, actually, though no one else seems to see witchers that way. His features soften around his wide eyes; often a tiny smile plays at the corner of his lips. Jaskier finds it stupidly endearing and it makes his chest feel warm every time it happens.
He tasks himself to see what he can do to coax more of those soft looks out of his witcher. Bathing seems rather effective at inducing it, as does fresh, hot food that he roasts over the fire. Sometimes it’ll happen when he reads to Geralt, and, on one memorable hot summer’s day, when they both stripped off to splash in a cool stream and Jaskier cheekily dunked him under the water.
Maybe it only happens when Geralt is relaxed, though Jaskier notices it happens even when he’s winding Geralt up and the two of them are bickering like an old married couple. Bickering surely can’t be relaxing, and yet there’s Geralt, pupils blown wide and giving him that soft look even while they argue about where they should camp for the evening and whether they should finish the last of the jerky.
Finally he gives in and asks Geralt about it, one night when the air is chilly and the two of them are pressed close together in their bedrolls to ward off the cold. Geralt huffs a laugh against his neck, the warm air sending goosebumps dancing over his skin. “Still haven’t figured it out?” he asks, and it’s fond and teasing, but that just leaves Jaskier even more confused.
“Let me know once you do,” Geralt hums into his hair, and puts an arm around his waist to tug him a little closer.