An optical see-through head-mounted display (OST-HMD) is a wearable device that has the capability of reflecting projected images as well as allowing the user to see through it, in contrast to typical head-mounted displays, which still use optical components, but are not see-through, such as virtual reality headsets. In some cases, this may qualify as augmented reality (AR) technology. OHMD technology has existed since 1997 in various forms, but despite a number of attempts from industry, has yet to have had major commercial success.