ED: ANSWER Diameter that works. Two times the largest radius. This is used
to figure out the smallest lens blank that needs to be cut.
B - ANSWER The height of the box or the distance between two horizontal
lines that meet at the top and bottom of the lens shape.
DBL - ANSWER How far apart are the lenses are
DBC – ANSWER How far apart the centres are? Look at GC. Frame PD
GC: The answer is The middle point of the box, the eye wire, or the shape of
the lens
OC: THE ANSWER Center for Optics. Point of not a prism
The FDA didn't allow cellulose nitrate to be used as a frame material. Why? —
ANSWER It was too explosive to be thought of as safe.
When did lenses start being put in frames? — ANSWER At the end of the
1300s
Who were the first people to make glasses? - Goldsmiths is the answer.
Frames made of which of these did not start being used until the 20th century?
— ANSWER Metal made of steel
Why does plastic work so well for making eyeglass frames? — ANSWER It's
very easy to shape and make.
What kind of extra care do nylon frames need? — ANSWER Soaking in water
several times overnight
to figure out the smallest lens blank that needs to be cut.
B - ANSWER The height of the box or the distance between two horizontal
lines that meet at the top and bottom of the lens shape.
DBL - ANSWER How far apart are the lenses are
DBC – ANSWER How far apart the centres are? Look at GC. Frame PD
GC: The answer is The middle point of the box, the eye wire, or the shape of
the lens
OC: THE ANSWER Center for Optics. Point of not a prism
The FDA didn't allow cellulose nitrate to be used as a frame material. Why? —
ANSWER It was too explosive to be thought of as safe.
When did lenses start being put in frames? — ANSWER At the end of the
1300s
Who were the first people to make glasses? - Goldsmiths is the answer.
Frames made of which of these did not start being used until the 20th century?
— ANSWER Metal made of steel
Why does plastic work so well for making eyeglass frames? — ANSWER It's
very easy to shape and make.
What kind of extra care do nylon frames need? — ANSWER Soaking in water
several times overnight
