Cindy Harris is the main villainess from The Nightmare Room episode "Four Eyes".
She was portrayed by Lynsey Bartilson.
Cindy was the best friend of the main protagonist, Jeremy Clark, who was getting a new pair of glasses to improve his eyesight.
However, Jeremy's new glasses allowed him to see actual aliens in their true form, and he learned of their plan to take over the world. While Cindy and Jeremy are at a barn party, Jeremy's glasses break so he could no longer see the monstrous faces of the aliens at the party.
At the episode's end, Cindy and her mother rescue Jeremy from the group of aliens that were chasing him. After Jeremy is seated in the back seat of their car, Cindy and her mother both reveal themselves as aliens.
While the other aliens (including Cindy's mother) possessed black eyes, the evil Cindy had red eyes, revealing herself as the leader. After the revelation, Cindy cackled evilly at a horrified Jeremy.