Purpose To investigate changes of vision-related quality of life during a 10-year period in a population with type 1 diabetes. Design Prospective cohort study. Participants Individuals who had their diabetes diagnosed before 30 years of age were considered to have type 1 diabetes (N=1210). Those who participated in both 14-year (1995–1996) and 25-year (2005–2007) follow-up examinations were included in the current analysis (N=471). Methods Vision-related quality of life was measured with the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). Main Outcome Measures Changes in vision-related quality of life scores. Results Loss of 3 lines in the Early Treatment Diabetic Retinopathy Study (ETDRS) chart was the most important factor related to negative changes in the NEI-VFQ-25 scores in our study after controlling for confounders. Most important changes were observed in subscales, such as general vision (−6.46 points), mental health (−10.19 points), role difficulty (−6.90 points), and driving (−10.43 points). Unemployment and the development of long-term complications, such as nephropathy, were also associated with negative changes in some NEI-VFQ-25 subscale scores. However, changes in diabetic retinopathy status were not related to changes in any subscale after 10 years. Conclusions Change in visual acuity was the most important factor associated with changes in vision-related quality of life scores in individuals with type 1 diabetes during a 10-year period. Our findings support the necessity of close follow-up of individuals with type 1 diabetes to avoid development of long-term complications and vision loss to improve quality of life. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.