Tapetum lucidum

The tapetum lucidum was a specific biological feature of an organic being's eye that could grant them night vision.

They were most famously possessed by cats, but some bloodlines on the Homeworld, (PROSE: The Bloodletters) such as House Arpexia, (PROSE: The Book of the War) also displayed them, giving them keen night-vision. The Corsair's eyes were described as "mirror-flecked". (PROSE: The Bloodletters)