PROBLEM TO BE SOLVED: To calculate the concentration of an optically active substance contained in aqueous humor more accurately, compared with when effects due to a cornea are not considered.SOLUTION: An optically active substance concentration calculation system 1 comprises a concentration calculation unit 40 which, for each of different wavelengths λ, λ, λ, and so on of light, acquires variations R, R, R, and so on of polarization state caused by passage of the light through an incident-side cornea 14A, an aqueous humor of an anterior chamber 13, and an outgoing-side cornea 14B, and then calculates a concentration C of a particular optically active substance contained in the aqueous humor by means of a least square method based on a theoretical formula R(λ) expressing the wavelength dependence of the variations of polarization state comprising both a matrix representing polarization characteristics of the incident-side cornea 14A and of the outgoing-side cornea 14B and a matrix representing polarization characteristics of the aqueous humor. The matrix representing the polarization characteristics of the aqueous humor is expressed by a function of a mathematical expression expressing the wavelength dependency of the optical rotation of the particular optically active substance. The mathematical expression includes a concentration value of the particular optically active substance as an unknown or a temporary known number.SELECTED DRAWING: Figure 2【課題】角膜による影響を考慮しない場合と比較し、眼房水に含まれる光学活性物質の濃度を精度よく測定することを目的とする。【解決手段】光学活性物質の濃度算出システム１は、異なる波長λ１、λ２、λ３、…の光のそれぞれについて、入射側角膜１４Ａ、前眼房１３の眼房水及び出射側角膜１４Ｂを通過したことによる偏光状態の変化量Ｒ１、Ｒ２、Ｒ３、…を取得し、入射側角膜１４Ａ及び出射側角膜１４Ｂの偏光特性を表す行列と眼房水の偏光特性を表す行列とを含む偏光状態の変化量の波長依存性を表す理論式Ｒ（λ）に基づく最小二乗法によって、眼房水に含まれる特定の光学活性物質の濃度Ｃを算出する濃度算出部４０を備え、眼房水の偏光特性を表す行列は、特定の光学活性物質の旋光度の波長依存性を表す数式の関数で表され、この数式は特定の光学活性物質の濃度値を未知数又は仮の既知数として含んでいる。【選択図】図２
