Everyone wants perfect vision: thanks to modern science contact lenses have make this possible without glasses. Designed to be invisible, the precision engineering that goes into these little lenses is often overlooked.
The client: Our client was one of the world’s largest contact lense manufacturers, producing 1.7 billion lenses per annum.
The challenge: When you are dealing with people’s vision, defects cannot be tolerated. Our client's quality control procedures involved each lense being inspected under a powerful microscope. If there was any damage to the window on which the lenses were placed, defects may not be spotted. With thousands of lenses passing over it each day, this window needed to be transparent and tough enough to withstand constant use without degradation.
The solution: Sapphire was the obvious choice for the material, meeting both the hardness and transparency specifications. Working closely with our client's research and development team we created a stepped window on which each lense rested during testing.
The window was a wholly custom part, and potentially very expensive. However, with our knowledge of the specific application, and the narrow range of wavelengths used, we were able to select a grade of sapphire that is mass-produced for a consumer product. This brought the cost down to little over that of an optical glass window.