What is the strange mark on the lenses of my new glasses? (---)?
I just bought a new pair of glasses last week and I noticed on my lenses that there is a mark that looks like two parenthesis with a solid line in the middle. (---) It looks something like this. I've never noticed it on the lenses of previous pairs of glasses, but my mother said she noticed that her lenses have the same mark. What is the point of this mysterious mark on the lenses of our glasses?
I don't have transition lenses :(
Help me solve this mystery!