Chi Luxin is one of the Heretical Colors, along with Paryl. Although not confirmed, it is highly likely that in order to see it, you’d have to be born with completely different eyes, just like with Paryl. How exactly a Chi Drafter’s eyes might be different is speculative, but judging by the way a Superviolet Drafter’s eyes will tighten to pinpricks, and that Adrasteia’s sclera moved along with the actual pupil, it may be assumed that a Chi Drafter’s eyes will tighten together so much that they become like a cats eye when viewing it, perhaps with the upper and lower sclera bunching up in an alien fashion.
It is noted that when Kip uses Chi and Paryl drafting during a powerful Luxin storm one of his eyes dilates fully turning black (in order to see Paryl) and the other turns almost completely white except for a tiny spot in the middle presumably his iris and pupil. This shows that drafting Chi causes the pupils to constrict to a minescule pinprick as the wavelength is so short.
Along with Paryl drafters, Chi drafters were hunted down and eliminated for being heretics by the Luxors of the Chromeria hundreds of years before the events of the books, because the Chromeria teaches that there are only seven colours of Luxin, as seven is Orholam's holy number.