Video See-Through Head Mounted Display and control method thereof

A VST-HMD (Video See-Through Head Mounted Display) includes at least one camera, a first display device, a second display device, a first lens, a second lens, a first eye tracker, a second eye tracker, and a processor. The camera captures environmental image information. The first eye tracker detects left-eye motion information of a user. The second eye tracker detects right-eye motion information of the user. The processor obtains an eye focus region of the user and depth information of the eye focus region according to the environmental image information, the left-eye motion information, and the right-eye motion information. The processor monitors a displacement of the eye focus region and a change in the depth information, and accordingly determines whether to adjust image positions of the first display device and the second display device.