A wearable device and a method of outputting a virtual image by the wearable device area provided. The wearable device includes a projection type display unit that includes a variable lens and configured to project a light forming an image, a first sensor configured to detect a light reflected from an eye of a user, and a processor configured to control to display the virtual image on the projection type display unit by controlling one of a location of the variable lens and refractive power of the variable lens based on retina image information corresponding to the detected light.