Head mounted displays (HMDs) are convenient tools for presenting visual imagery. The usefulness of HMDs can be extended by integrating eye tracking and voice recognition with the HMD, creating a true hands-free interface. We have developed a low-cost eye tracking system for an HMD using commercially available hardware and easily configurable software developed in-house. This system, along with commercial speech recognition, allows us to control computer applications without the need for a keyboard or mouse.