Fluid lens focuses like eye, as reported in Nature Science Update, 19 Mar 2004. Engineers at Phillips Research, Endhoven, The Netherlands have developed a tiny liquid lens that can change its focal length in the same way the lens in the human eye does by changing the curvature of its surface. The lens consists of two types of fluid, one water based, the other oil based, inside a cylinder lined with a water repellent chemical. This pushes the water away from the sides of the cylinder so that it forms a hemispherical shaped droplet surrounded by the oily fluid. The curved interface between the oil and water bends light. When an electric field is applied to the cylinder, the inner coating becomes less water repellent, the water droplet becomes less curved, and light is not bent as strongly. This means the focusing power of the lens can be controlled by adjusting the electric field. The cylinder is only 3mm across and 2.2mm high, so it will useful in miniature cameras and medical endoscopes.
Editorial Comment: This is a good illustration of how a created object is the result of an intelligent designer making use of the laws of physics and the properties of matter to achieve a purpose. The matter and energy alone could not make the lens. The same must be said for the lens in a human eye. It is made of matter that obeys the laws of physics, but the fact that it does so in a useful way is evidence it was designed and built by an intelligent creator. (Ref. eye, lens, engineering)