What do different charts test and what are the differences?
Visual acuity charts are recognition charts that test how well students/children can clearly identify optotypes at a certain distance. Some charts inadvertently test cognitive development instead of visual acuity. For example, the Tumbling E requires direction and orientation skills, which are developmental skills that do not emerge at the same time. Up and down makes sense; left and right is abstract. You may want to avoid Tumbling E for children younger than 3rd grade.
