Science and Speculation (non-canon)[]
The unnamed species that Han-jee is a member of presents considerable challenge to current understandings of neurology and its limits. While the limits of Han-jee's perception via its separated eyes was never outlined specifically, it is clear that these eyes can seemingly transmit across as far as metras of space without material connection. Could the eyes transmit millions of metras between planets and star systems?
These tramsissions may be achieved through any number of ways. While the speed of update between eye/host is never completely revealed, it is implied to be instantaneous. Thus, we may be able to rule out pheremone encoded transmissions, bioradiological transmissions, or subsonic transmissions. What may be a more intriguing and exciting possibility is that transmissions may result from neurological form of quantum entanglement.
This real physical phenomenon remains mysterious even to the most knowledgeable physicists, but has been described as "spooky motion at a distance." It has been mathematically calculated, (and disputedly observed), that two particles so quantumly entangled have the abilty to change properties in tandem even if separated by distances that should preclude such instantaneous communication. It has been speculated that such particles could some day be utilized for mainstream communication where normal communication would be impractical, such as across vast distances of space. It has also been speculated in fringe science literature that such quantum entanglement may be responsible for the "paranormal" phenomenon of family members sensing each other at a distance, or a number of other so-called "psychic" phenomena. No hard, credible science has yet to emerge in this area, but is an interesting speculation.
However, within the context of a vastly alien physiology, such particle entanglements might be common. Allowing a distant separated sensory organs to quantumly communicate with the host body. The light-sensing organs of the distant eye might be capable of transforming these stimuli from a chemo-electric signal into a quantum entangled signal by modifying the properties of one half of a single pair, or perhaps even numerous pairs, of entangled particles. These instantaneous changes in properties would then be retranslated into chemo-electrical signals and transmitted to the brain of the host organism.
How such an adaptation could arise through natural selection strains the imagination even further. It would seem more likely that a species with a potential predisposition arose on some planet. Then either their own scientists or some species-external scientists altered the species to its current state. Whether the alteration was genetic, or bio-mechanoid, remains unknown.