A method for non-invasive blood glucose monitoring includes the following steps. At least one ray of light is emitted from at least one light source. The light emitted from the light source is leaded into an eyeball and focused on the eyeball through a first beam splitter. The reflected light reflected from the eyeball is transmitted through the first beam splitter to a set of photo detectors. Optical angular information and absorption energy information of the reflected light transmitted to the set of photo detectors are measured. Optical angular difference and absorption energy difference resulting from the light emitted from the light source and the reflected light transmitted to the set of photo detectors are obtained. Glucose information is obtained by analyzing the optical angular difference and the absorption energy difference, and since glucose information has a corresponding relationship with blood glucose information, blood glucose information may be read.
