
...in the Star Trek episode,
"Let That Be Your Last Battlefield"?
The Big Bang Theory Season 4, Episode 21

...Star Trek: The Next Generation
Geordi La Forge without his VISOR...
The Big Bang Theory Season 1, Episode 14

Star Trek style.
The Big Bang Theory Season 5, Episode 23

Star Trek: Deep Space Nine
trivia,
The Big Bang Theory Season 5, Episode 17

You can go dressed
as a Star Trek science officer...
The Big Bang Theory Season 2, Episode 2