Visual functions that affect vision-related quality of life (VR-QoL) before and after intravitreal injection of ranibizumab in patients with cystoid macular edema secondary to central retinal vein occlusion (CRVO-CME) are poorly understood. This multicenter, open-label, single-arm prospective study included 23 treatment-naïve patients with CRVO-CME. The best-corrected visual acuity (BCVA), letter contrast sensitivity (LCS), severity of metamorphopsia (M-CHARTS), amount of aniseikonia (New Aniseikonia Test), and stereopsis (Titmus Stereo Test and TNO stereotest) were examined every month from before treatment to 12 months after treatment. For VR-QoL assessment, the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) was provided to the patients before treatment and at 3, 6, and 12 months after treatment. Stepwise multiple regression analysis revealed that the BCVA of the fellow eye was related to the VFQ-25 composite score before treatment, and that the BCVA of the fellow eye and TNO values were related to the VFQ-25 composite score 12 months after treatment. Changes in LCS were significantly correlated with changes in the VFQ-25 composite score. In patients with CRVO-CME, visual acuity of the fellow eye had the strongest impact on VR-QoL. The contrast sensitivity of the affected eye and stereopsis were also associated with VR-QoL.