Oculus

The oculus was a supposedly Vulcan cybernetic implant that Sam Rutherford received after being severely injured in an accident during his time at Starfleet Academy. Then-Lieutenant Commander Les Buenamigo had the cybernetics installed on the left side of his skull -- programmed to make him falsely believe he'd chosen to receive it to assist with engineering -- and all memories of the "program" and the officer involved were erased on Buenamigo's orders; as a side effect of this neural reprogramming, he developed a new, more strait-laced and carefree personality which carried forward for most of his career thereafter. (LD: "Second Contact", "First First Contact", "Reflections", "The Stars At Night")

The implant would occasionally act up due to Rutherford's original personality trying to reassert itself. (LD: "Reflections")

In 2380, Rutherford's original oculus was destroyed when Lieutenant Shaxs ripped it from his face and left it behind on a Pakled Clumpship in order to save Rutherford from Badgey's attempt to kill him. The remnants of it survived the explosion and were later recovered along with Badgey by the Drookmani. However, as a result of the loss of his implant, Rutherford lost his long-term memory. (LD: "No Small Parts", "The Stars At Night", "A Few Badgeys More")

The destroyed oculus was subsequently replaced with a new identical device. (LD: "Strange Energies")

In 2381, Rutherford's implant acted up again. This time, it caused him to experience the moment of his accident as a recurring nightmare. When D'Vana Tendi tried to erase the memories from his implant's cache, it caused his older, more aggressive personality to reassert itself, explaining that the brain was too complex for the memory wipe to have actually worked, instead leaving Cadet Rutherford locked away. Rutherford's many glitches and strange emotional quirks were a result of his previous personality trying to reassert itself. The two agreed to a race to decide who would control their body with Cadet Rutherford reconstructing the Sampaguita while Ensign Rutherford reconstructed the Delta Flyer with his closest friends serving as his crew. Ensign Rutherford won, and Cadet Rutherford vanished for good so that the person he had become could live on. Finally accepting that Starfleet had made him a better person, Cadet Rutherford urged his newer self to hold onto the friends that he had made. As a result, Rutherford was able to remember at least some parts of his past, most notably the fact that his implant was installed to cover up illegal activities, rather than voluntarily. However, Rutherford was unable to remember who was behind it. (LD: "Reflections")

After discovering the truth behind the Texas-class automated starships, Rutherford regained his memory of the fact that now-Vice Admiral Les Buenamigo was responsible for him having the oculus. Despite this, he chose to continue using the oculus following an attack caused by the vessels' emotional instability because he found it too useful to give up. (LD: "The Stars At Night")

In an alternate reality, by 2382, Rutherford had become mostly cybernetic rather than having just an oculus implant. (LD: "Dos Cerritos")

While on a break in 2382, Rutherford spent the morning trying to connect his oculus to the systems of the USS Cerritos without any success. The oculus suddenly shot a plasma beam that nearly hit Brad Boimler despite the fact that it was not supposed to be able to shoot plasma. (LD: "Fissure Quest")

After his oculus caused problems during the effort to stop a destructive soliton wave, Rutherford gave it up for good, instead becoming fully organic even after the crisis was over. Afterwards, he noted that the implant came with a dopamine inhibitor that was interfering with his ability to make romantic connections with people, causing Rutherford's feelings for Tendi to become obvious for the first time with it gone. (LD: "The New Next Generation")