Optical system for implementing augmented reality and device including the same

An augmented reality optical device includes an image generator receiving a preset wavelength range of light reflected by an affected part and generating an affected part image, an image output unit outputting a visible wavelength range of light corresponding to the affected part image, a first mirror unit reflecting the light output from the image output unit, a lens unit focusing the reflected light, a beam splitter reflecting a preset wavelength range of light incident from the outside in a preset direction and transmitting a portion of an incident visible wavelength range of light to a user's pupil (or in the preset direction) while reflecting another portion of the incident visible wavelength range of light in the preset direction (or to the user's pupil), and a second mirror unit re-reflecting the preset wavelength range of light reflected by the beam splitter to the image generator.