Aim: to evaluate the maintenance of visual functions by administering eye drops which prevent lens opacities in patients with a scheduled cataract surgery based on the stages of cataract development. Patients and Methods: 822 patients with a scheduled cataract surgery were recommended with the instillations of Catalin® (1 drop four times daily). The patients were divided into two groups, i.e., the study group (364 patients who used the eye drops throughout the waiting time) and the control group (195 patients who refused the eye drops for various reasons). Both groups were additionally subdivided into three subgroups, i.e., I (mature cataract), II (immature cataract), and III (early cataract). Exclusion criteria (n=263) were irregular instillations or the use of Catalin® analogues. Results: the average waiting time was 6.76±1.35 months. A decrease in uncorrected visual acuity (UCVA) by 37% and 40% was revealed in the study group and the control group, respectively. Additionally, a myopic shift of the spherical equivalent was detected. Significant differences (р