Are those glasses for adults or children?
There are five sizes available.
Blue for 20+ years old (15.2cm)
Light Blue 18+ years old(15cm)
Black for 14 to 20 years old (13.7cm)
White for for 10 to 16 years old (12.8cm)
Orange for 8 to 14 years old (12.4cm)
What is the lenses made out of? Glass or Polycarbonate?
The lenses are not glass, they are made from plastic material, easy to remove and easy to replace with custom lenses.
Can the lens be replaced with prescription lens?
Yes, if you have a tool, you can exchange the lens.