I do realize this is kinda an unnecessary post to make, but I'm seeing a lot of confusion on what Chase realized on seeing Violet's eyes after this week's episode and ehhhh
Human eyes and Key eyes look different. Human eyes are drawn half black-half eye coloured, while keys have gemstones for eyes with only a small black dot for a pupil.
When we see Buddy's past as a human, we see his human eyes too, which are different from his current eyes
I need everyone to remember that "A murder, unfortunately" was the first time Chase knowingly saw keys in their human form. Yes, Buddy had different eyes from others, but for Chase to have assumed that it is because he's a key would be far too big of a stretch before now.
Even among keys, the way the eyes look is different because they're all cut of of different stones. Sil and others have gemstones which are cut into reflective facets, which amplifies the shiny nature of the stone and slightly obscures the pupil in the centre. On the other hand, Buddy and Vi's eyestones are more of a polished surface, thus their pupils are more visible giving them a more human look.
It was not the above four keys' eyes, but Violet's which helped Chase realize it. And no, it's not because Buddy and Violet have the same eye colour, they don't. Violet's eyes are multicoloured, similar to the colour of her underskirt. Buddy's eyes are blue. (Also, having the same eye colour does not make people related ðŸ˜ðŸ˜)
It's because Chase knew by then that keys had stone eyes in human forms. And seeing Violet's eyes made him realize that not all stones look sparkly like Silver's. He noticed the same non-human gemstone quality of both their eyes, and thus reached the conclusion that Buddy is a key.
When Buddy dragged him to the mirror to show him Violet's human form, I don't think he was particularly trying to point out her eyes. Buddy was pointing out how keys can look very human, how he looks very human, but is not a human. But he never got to finish talking. Chase noticed the eyes and reached the desired conclusion anyway because he's just that smart.
