You should watch:

Eye of the Beholder

This was episode number 18 of season 7.

The following characters appeared in this episode:

(uncredited) Ensign Jae
(uncredited) Ensign Kellogg
(voice) Enterprise Computer
Captain Jean-Luc Picard
Counselor Deanna Troi
Commander Wiliam T Riker
Doctor Beverly Crusher
Ensign Maddy Calloway
Lieutenant Worf
Lt Commander Data
Lt Nara
Lt Commander Geordi La Forge
Lt Daniel Kwan
Lt Walter Pierce
Man
Woman