Basic spectacle frame parameters – boxing system
Introduction
Spectacle frame measurement called boxing system is used especially in central Europe. We measure and calculate spectacle frame parameters related to the box. These boxes copy inner shape of the spectacle eye frame. Centre of the eye frame is defined as the crossing of the two diagonals. Position of the eye frame center will differ from axis measurement. The difference increases with the eye frame asymmetricity.
Goals
- Draw spectacle frame schematically
- Draw boxes into the eye frames
- Measure basic frame parameters and note it in the scheme
Equipment
Spectacle frame, ruler or millimeter ruler, writing equipment, calculator.
Methods
Draw spectacle frame schematically
Put the frame with the front side on the paper and draw the outer and inner shape of the frame.
Draw boxes into the eye frames
In both eye frames draw the boxes. Diagonals of the boxes creates eye frame centers. Distance of these centers defines frame size (OR).
Measure basic frame parameters and note it in the scheme
Results
Draw spectacle frame schematically
Draw boxes into the eye frames
Measure basic frame parameters and note it in the scheme
OR =
d =
a =
b =
Discussion
All measured parameters in boxing system are related to the box. These boxes are drawn into the eye frames. For example, bridge size is the nearest distance between eye frames. Eye frame height is the longest distance from lower to upper inner side of the eye frame. This system is more reliable than axis system.
Conclusion, notes, comments
Which symbol on the frame or frame side notes the boxing system?