This study explored the impact of idiopathic infantile nystagmus syndrome (IINS) on quality of life in adults measured using the VFQ25 questionnaire. Of 38 subjects, 35 completed the questionnaire. Mean age was 35.1±13.0 years; 15 were British Caucasian and 14 females. Overall mean VFQ25 score was 65 (SD 13). Perceived general health (mean 68, SD 21) scored higher than overall vision (mean 59, SD 15). Ocular pain, colour vision and social functioning scored high, i.e. least impacted. However, effects on mental health were low (mean 45, SD 21) along with effects on role limitations and dependency. The quality of life values did not correspond with the visual acuity measurements. The authors conclude that current clinical assessment may grossly underestimate the real-life effect of nystagmus. The VFQ25 questionnaire may provide more functional information on the impact of nystagmus on quality of life.