TWOK Directors Cut extra footage

[Boadrummer]

According to Memory Alpha, "At least one line of the extra footage ties directly to a scene from Star Trek IV: The Voyage Home, helping to make the continuity between the movies that much more cohesive."

Does anyone know what scene this references?

 

[Oso Blanco]

That must be the line about the glasses being 300 years old.

 

[number6]

McCoy makes a comment about how hard it was to find those glasses with the lenses intact.