A head-mounted display is an electronic wearable device, mounted on a head that includes a small display optic near the eye. The display optic projects a virtual environment in front of the user's eyes. The screens used in the head-mounted display are liquid crystal displays (LCDs) since they are compact, efficient, and lightweight. HMD finds applications in a variety of industries including military, gaming, medical, sports, training and simulation, engineering, etc. The virtual reality headsets used in gaming and other applications are HMDs combined with inertial measurement unit (IMU). Furthermore, optic head-mounted display (OHMD) is a wearable display that can reflect projected images and enables the user to see through it.