Alzheimer's disease (AD) is a neurodegenerative disease that occurs especially in advanced ages. It reduces quality of life of both the patient and their relatives. In addition to its primary effects, AD causes metabolic defects and tissues are damaged due to these effects. Oxidative stress damages cells by disrupting antioxidant/oxidant balance in many tissues, especially due to AD. In individuals with AD and the elderly, lens tissue is damaged due to oxidative stress and may cause vision loss. Therefore, it is very important to investigate herbal products that both prevent/cure AD and reduce AD-related oxidative stress, as they may have fewer side effects. In this study, the protective effects of parsley extract on lens tissues of experimental AD model induced by scopolamine were examined and evaluated through biochemical parameters. The result of biochemical experiments and principal component analysis, it was observed that parsley extract had a therapeutic effect by reducing oxidative stress in lens tissues of experimentally induced AD rats. It can be suggested that the phenolic and flavonoid-rich content of parsley extract may have caused the reduction of oxidative damage in lens tissues and can be used to protect lens tissue against oxidative stress due to AD disease.