SCD and Schnyder corneal dystrophy: SCD knowledge was significantly associated with the parent's age (p = 0.005), age of the children (p < 0.001) and education level (parents with primary, p = 0.014; secondary, p = 0.052; tertiary education, p = 0.065, had higher SCD knowledge scores compared to those with no formal education) in the univariable analyses.