| 摘要 |
PROBLEM TO BE SOLVED: To provide optical glass having higher abnormal dispersibility, so that the optical glass can compensate chromatic aberration of a glass lens with high precision, having a high index of refraction, a low dispersibility (high abbe number), an abrasiveness lower than the glass of the prior art, and thus the optical glass being easy to be ground for processing; an optical element; and a preform.SOLUTION: Optical glass includes P, Al, and Mgas cationic ingredients, and contains Oand Fas anionic ingredients, wherein the ratio ((Mg+Ca)/R) between the sum of the Mgcontent (cation%) and the Cacontent (cation%) and the total content of alkaline earth metals (R: cation%) is 0.25 or more, and the abrasiveness is 440 or less. |
