Red-eye

Red-eye was a condition that the Ood were commonly afflicted with. Its symptoms were bright red eyes, rabid temperament and anti-human sentiment.

When the Beast took control of the Ood working in Sanctuary Base 6 on Krop Tor, it resulted in the Ood becoming subject to red-eye, signifying their possession. (TV: The Impossible Planet, The Satan Pit)

On the Ood Sphere, red-eye was caused by the subconscious of the Ood Brain reemerging amongst the Ood after 200 years of slavery, due mostly to the sabotage of Ood Operations's systems by the Friends of the Ood. It led to the Revolution of the Ood in 4126 and the freedom of the Ood. (TV: Planet of the Ood)

When telepathically mediating through time, members of the Ood Council led by the Ood Elder became afflicted with red-eye upon receiving a vision which they used to warn the Tenth Doctor that the return of the Master is inevitable. (TV: The End of Time).

The Eleventh Doctor once encountered an Ood with red-eye. (COMIC: Take a Bow (Tie))

An Ood with red-eye and a bandaged head appeared on a television advertisement for Lawyers Against Time Lords. (COMIC: No Win, No Fez)