Noting that the reflective qualities of Michael Fremer's record collection could be responsible for his listening environment, I don't see that a pair of glasses being regarded as a reflective surface only inches from our receptors [ears] wouldn't make a meaningful difference as well. I wonder if the engineers who designed the famous Neumann KU-100 microphone in the shape of a human head ever considered a special model wearing eyeglasses ?
Try it even if you don't regularly wear eyeglasses and if you don't hear a difference may I suggest a visit to a hearing specialist ? It definitely makes a difference
What if you wear John Lennon specs? You are not the first to make this recommendation as Jim Smith makes it in his book but there is no way on Earth a reviewer's perspective is skewed off base due to failing to remove eyeglasses. What's next, mandating a uniform size and shape of ears? Augmenting or reducing the size of the schnoz? What about beards? Yarmulkes and Taqiyah?