Why special glasses in movies and TV?

Factual Questions
1

Has anyone ever noticed that when someone wears glasses in a movie or a TV program that the lenses in these glasses are flat rather than curved as in real life? They must go to a lot of trouble to have flat lenses installed because even if you order a pair of glasses with no correction, the lenses will be curved. Why?

Whenever I notice this it totally subverts the illusion that the movie is portraying something in real life. For instance when a TV newsperson is supposed to be interviewing someone at an accident scene and the subject is wearing these dorky flat-lensed glasses.

Another other thing that can subvert this illusion is when you see women wearing hair-do’s of the style when the movie was made rather than of the time period portrayed. For instance a 70’s style hairdo in a movie that is supposed to be taking place in the 1940’s. But I guess this is a subject for another thread.

2

My guess as far as the sunglasses is that it avoids reflection of studio lights. That’s why sometimes actors wear frames with no lenses anyway.

3

Two reasons:

  1. The person is wearing the glasses as a costume (think “smart girl” look), not because they need them to really see. Real glasses would make them see funny and get headaches.

  2. Real glasses with curved front surfaces would reflect the lights (and there are A LOT of them on a TV/Movie set) all over the room (remember the curved front reflects from all directions – like a mirrory christmas ball). The result would be one or more annoying “hot spots” that would not easily go away. Flat lenses reflect in one direction only; as long as there are no big lights there, there are no hot spots.

4

Plus “real glasses” distort your face as they shrink or enlarge your eyes and the face around them if your prescription is high enough. I would assume actors who need glasses probably wear contacts and then plane glass glasses for the character so as to not distort their features.

5

The dude who played Clark Kent on the original Superman series wore glasses with no lenses at all. This was common practice back then, but when TV quality got better people started to notice, so they switched to fake flat lenses.