CAT and diabetes mellitus: This efficient entry of EGCNPs in HLECs allowed the nanoparticles to exert anticataract actions that were demonstrated in: (1) their ability to replace the activity of the catalase enzyme; (2) improving the ratio between reduced and oxidised glutathione (GSH/GSSG); and finally, (3) their ability to provide a significant protection against the glycation of lens proteins, which is one of the major causes of cataract, particularly in diabetics.