Visual dysfunction after mild traumatic brain injury (mTBI) is common but often remain undiscovered during longer periods of time. No valid, reliable and easy-to-use screening instrument for uncovering visual dysfunction exists. Furthermore, it is unknown whether optometric measurements currently used in assessing vision problems are consistent with patients' subjective complaints experienced in everyday life. A better understanding of patients' visual challenges combined with objective measurements, will contribute to a better and more efficient diagnostic investigation and treatment. The aim of this study is to get a better understanding of patients who are suffering from visual dysfunction after mTBI. This understanding will be gained by: 1. developing and validating a questionnaire for uncovering subjective visual complaints in subjects with mTBI. 2. developing eye tracking based screening tools applicable both in- and outside of optometry clinics 3. examining relationships between self-reported data, eye tracking measurements and optometric measurements. The study will consist of N = 200 subjects. N = 100 of the subjects are suffering from mTBI (commotio group). The second group N = 100 is the non-injured group that preferably will consist of relatives to the subjects in the commotio group. The subjects in both groups have to answer the questionnaires regarding subjective visual complains, undergo optometric tests and undergo eye tracking measurements.