An opthalmologist was a doctor working in the eye section of the Bi-Al Foundation. In 5000, he examined Lowe, who then infected him with the Swarm.
After the Nucleus was taken out of the Fourth Doctor's body, he, Lowe and a medic escorted it to Titan Base. He was posted to guard the breeding tanks, but was shot and killed by K9. (TV: The Invisible Enemy)