test symbol that has a line width of less than 1 minute of arc, then their visual acuity will be 1. If the person being tested has a visual acuity of only 0.5, then the test symbol displayed must be doubled
Visual acuity 0,7 Reading a telephone directory Visual acuity 0,5 Reading the newspaper Visual acuity 0,4 Watching television Visual acuity 0,1 Orientation outdoors As the table shows, a very clear distinction