Virtual worlds were first developed by architects, toy manufacturers and military engineers to build better houses, more realistic fantasy games and deadlier weapon systems. Now virtual reality is making a huge impact in the filed of medicine. Virtual reality allows surgeons to practice new techniques before operating on the patient. Computer models simulate complications that might arise during surgery. And virtual reality provides the ideal training form medical students. The virtual scalpel simulates tactile feedback - the student can explore, experiment and even slip, but do no harm. An interactive multimedia simulation of a cataract operation may transform eye surgery education for Third- World doctors. In plastic surgery, a mouse and special software is used to plot and test a surgical procedure on a 3-D scan of the patient's face. Ultrasound images are turned into a 3-D visualisation of a foetus in the mother's abdomen thereby making risky procedures such as amniocentesis much safer as the physician can clearly see the location of the needle relative to the foetus in 3-D space. Virtual reality also means using computes to facilitate remote surgery, remote diagnosis between doctors and patients at different locations, and telemedicine whereby doctors in virtual operating theatres or virtual examining rooms will be linked via electronic communications.