A method for classifying a cataract of an eye to determine parameters for pre-setting phaco-treatment instruments. OCT-based measurements are realized. The OCT-based scans are analysed using imaging technology and the local distribution of the cataract is determined. The cataract is classified on the basis of comparison values and the local distribution and classification of the cataract are used to identify parameters for pre-setting phaco-treatment instruments. Even though the proposed method for classifying the cataract of an eye is provided for determining parameters for pre-setting phaco-treatment instruments, it should equally also be used for determining parameters for pre-setting treatment instruments based on fs-lasers.