Varioptic of Lyon, France, has announced that it will enforce the patents it holds on the use of electrowetting technology to create variable-focus lenses. The determination follows Netherlands-based Royal Philips Electronics' statement in March that it plans to demonstrate fluid lenses based on that technology for high-volume manufacturing. Varioptic issued a letter to Gerard Leisterlee, chairman, president and CEO of Philips, requesting on what basis it intends to use the technology without a license or other agreement. After receiving a response, the company took legal action.