The depth, contour and angle of the glazing grooves of spectacle frames: don't blame the glazer?

The groove of a spectacle frame is responsible for lens retention. It also tends to fill with unsightly dirt which cannot be readily removed by our patients. The results of this investigation would suggest that both loose spectacle lenses and dirt accumulation may often be due to poor quality control in the frame industry. The data also suggests that unwanted stress may be present in both frames and lenses due to non-optimal groove shape.