Thanks to the wonders of HD I just noticed that Jonathan Frakes has a bandage around his right index finger in "Sarek" and "Ménage à Troi".
I'm watching Menage now, and just noticed something new. Starting at 4:30, there's an Asian guy sitting behind Lwaxanna and the Ferengi in Ten Forward. He's wearing glasses. About 15 seconds later, after we cut to Deanna and Riker at the bar, then back to Lwaxanna, the glasses are gone.
Did we ever see anyone else wearing glasses in TNG?