The biomicroscope can be used to measure the rotation of soft toric lenses.
To measure the rotational position of a soft toric lens, locate the mark on the lens indicating the base of the prism. This is usually near the 6 oΓÇÖclock position. Using a narrow parallelepiped, adjust the height of the instrument such that the center of the beam is approximately in the center to the pupil. Rotate the beam until it goes through the mark on the lens and the center of the pupil. The amount of rotation can than be read from the scale.
