The lens is then inverted and the whole optical bondline is given an even cure. Another method for precuring is to have the light at a very low angle to the top lens surface. The low angle of light is able to reach the edges in many cases. In summary, Norland Optical Adhesives will do an excellent job of bonding precision optical components when properly handled. If separations do occur, first identify if it is adhesive or cohesive failure and then take the appropriate steps to correct them.
Bondline edge receives no light.
Precure only bond joint. Low angle of light reaches bondline edge.