Disclosed is a method of quantitatively assessing whether the progress of an operation that enlarges a patients clear vision region is satisfactory. A chromatic vision measurement is carried out on a patient who has received an operation that enlarges the patients clear vision region, such as an operation that inserts a multi-focal lens into an eye to treat cataracts. The chromatic vision measurement data is compared, i.e., quantitatively assessed, with reference data (reference data obtained by carrying out chromatic vision measurements on a large group of people), in a quantitative assessment means. It is thus possible to objectively and appropriately assess whether a patients post-operative progress is satisfactory.
