Tag fan and block test for astigmatism

Astigmatism fan chart

astigmatic fan test

The astigmatism fan chart has line differences in 10 degrees intervals. Some charts have correcting cylinder axis marked in chart written at top of each spoke of line (Figure 1) and some charts just only represent the actual representation of…

Astigmatism charts

Astigmatic fan test

Two of the most commonly used astigmatism chart are the Clock dial chart and the astigmatism fan chart. This test well controls accommodation as fogging is done prior and has an advantage over the Jackson cross cylinder where one of…