Corrected entry: Patrick, the elderly and child-like one of the visiting genetically engineered trio, appears in the background with his reading glasses for ~3 seconds. Mature actors in the 20th century need glasses. Mature genetically enhanced people of the future never wear glasses except that one scene.
Corrected entry: During the fleet battle Sisko says, "Evasive maneuvers, Pattern Omega. We're going through." After he says this, there is a flash of light on the bridge. During the flash, if you look closely, there is a ship diagram in the background behind Sisko on the left side of the screen. This is a diagram of an Excelsior-class ship, and the Defiant is NOT an Excelsior-class starship.