Head-Mounted Displays (HMDs) are wearable devices that provide immersive visual experiences by placing screens directly in front of the user's eyes. They are commonly used in virtual reality (VR) and augmented reality (AR) applications, allowing users to interact with digital environments or overlay digital information onto the real world. HMDs typically consist of two small screens, one for each eye, and may include sensors to track head movements. This technology is utilized in various fields, including gaming, training simulations, and medical applications, enhancing user engagement and providing new ways to visualize information.