Vergences #
We now move to the section on Vergences, where we find two links that lead us, respectively, to a vertical column and a horizontal row of 6/12 VA letters (equivalent to 20/40, 0.3 log, 0.5 decimal). These lines of letters can be used as a stimulus when performing the test for vertical and horizontal fusional vergences, respectively, using the Risley prisms or a prism bar.
Vertical column
Horizontal row
This row and column could also be used for measuring horizontal and vertical heterophoria, using the von Graefe technique.
As usual, the chart has a pair of zoom buttons to modify the size of the letters in 0.1 log steps (we can also use the “+” and “-” keys). The size chosen in the last execution of the program will be automatically saved for the next session.
If we want to vary the combination of letters, we can use the corresponding icon from the tool menu, or the “Z” key on the keyboard. To return to the initial letters, we have another icon, or we can also press the “X” key.