Does blending an RGP lens move or remove plastic?

Blending of RGP lenses is widely used to Increase patient comfort while wearing the lenses. The blending process smooths the peripheral curves of the lens, but it has not been determined if this process moved or actually removed the lens material. Twenty fluoroperm 30 bicurve, unfinished lenses were weighed on a Sartorius analytical balance to the ten-thousandth of a gram. The lenses were then modified with a tool that would simulate the blending process and reweighed. The data was then compared using a paired one-tailed t-Test and the results were shown to have a statistically significant lower lens weight. Thus, we determined that blending actually removes the lens material