Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and trifunctional protein (TFP) deficiencies are inherited disorders of long-chain fatty acidmetabolism caused by mutations to the genes encoding for the mitochondrial trifunctional protein. A progressive retinopathy occurs in both disorders and researchers have observed a faster progression of retinopathy in patients with LCHAD deficiency compared to TFP deficiency. This study used a modified version of the National Eye Institute 25-item Visual Function Questionnaire to assess the areas of vision that are affected in these patients and compared survey scores to evaluate whether the progression of retinopathy differed by genotype. We also examined factors thought to be related to retinopathy progression and their relationship with survey scores of visual functions. This study provides insight into the aspects of visual function and perceived effects of vision impairment on vision and socioemotional outcomes in subjects with LCHAD and TFP deficiencies.