Redox pathways involved in oxidative stress in the eye lens. AFR·, ascorbate free radical; AFRR, NADH-dependent ascorbate free radical reductase; DHA, dehydroascorbate; GR, GSSG reductase; GSSG, oxidized glutathione; GSH, reduced glutathione; PDI, protein disulfide isomerase; PSH, sulfhydryl-containing protein; PSSG, glutathionated protein; PSSP, oxidized disulfide bond-containing protein; ROS, reactive oxygen species; TrxR, thioredoxin reductase; Trxox, oxidized thioredoxin; Trxred, reduced thioredoxin; TTase, thioltransferase.