The effect of low-intensity laser irradiation on the processes of lipid peroxidation in lens homogenate and aqueous humor during experimental diquat-induced cataract of rabbit eyes was studied. The levels of primary and secondary products of lipid peroxidation (LPO), conjugated dienes and thiobarbituric acid reactive substances (TBARS), were evaluated. We found that the experimental cataract model leads to a significant increase in the content of conjugated dienes and in the content of TBARS both in lens homogenate and in aqueous humor. The data obtained support the important role of oxidative stress in the development of the diquat-induced cataract model. Low-intensity laser treatment does not provoke a significant decrease in conjugated dienes or in TBARS in either lens homogenate or aqueous humor. Although our therapeutic scheme led to a slightly decreased level of LPO products, we conclude that the effect of low-intensity laser-irradiation may depend on the dose applied, individual tissues and other factors.