The inside of an anterior chamber (21) of a human eye containing the protein molecules of albumin and globulin is irradiated with laser light beams having different wavelengths from a variable-wavelength laser light source (10). Scattered light from the protein molecules is received by a detector (8), and an autocorrelation function of the scattered light signal is determined by a correlator (9). A computer (11) computes the concentrations of albumin and globulin or the ratio thereof on the basis of the autocorrelation functions of the scattered light signals of the albumin and globulin irradiated with the laser light beams having different wavelengths. In such a configuration, the concentrations of albumin and globulin, or the ratio thereof can be measured reliably without contact and in a noninvasive manner.
