An eyeglass device with a detachable lens unit has a frame and a lens unit. The frame has a first end and a second end in width each connecting to a foot, and has an intermediate between the first and second ends extending out a connecting base with a recess. The lens unit comprises two lenses and a connecting piece between the two lenses to snugly engage with the recess of the frame. Thereby, the lens unit and the frame are combined together and positioned and thus the attachment or detachment of the eyeglass device is convenient.