True 5:1 concentration. 1  Double the strength of other brands. 2  Minimal or no fillers and binders. 3  No pharmaceuticals, sugar, or dyes. 4  Comprehensive lab testing (e.g., heavy metals,etc.) 5  Made in a cGMP certified facility. 6  Unbeatable value. 7  Safely used in the USA since 1995.
Arrow Length - refers to the length of the arrow shaft. Arrow size - refers to the spine (stiffness) of the arrow. The shaft size is always referring to the diameter of the shaft, the wall thickness of the shaft and the distance that the arrow shaft will flex before it bends or breaks.
Remove the glasses and use the PD ruler to measure from the line you drew to the bottom of the frame. Safevision.net notes that this measurement is called the B measurement or segment height or seg height of a bifocal. Most bifocals are measured between 9 mm and 20 mm from the bottom of the frame. Record the measurement of the right bifocal and repeat the process with the left lens, measuring from the bottom of the frame to the top of the lower lid. Draw a line on the lens at the top of the lower lid.