While performing the astigmatic clock dial, if the clearest line is at the 2-8 position and the least clear line is at the 5-11 position, what is the corresponding axis of astigmatism?

The axis of astigmatism is determined by the position of the clearest and least clear lines observed during the astigmatic clock dial test. In this case, the clearest line is at the 2-8 position and the least clear line is at the 5-11 position.

To pinpoint the axis, it is essential to understand that the meridian corresponding to the clearest line is the one that is perpendicular to the axis of astigmatism. The axis is measured in degrees, with 0 degrees aligning with the horizontal meridian.

To find the corresponding axis, you take the position of the clearest line (2-8) and determine where the axis of astigmatism lies. The position of the clearest line at 2-8 is essentially 90 degrees, as it falls directly vertical when considering the standard clock dial orientation. The least clear line at 5-11 represents a line that is 90 degrees perpendicular to the 2-8 line.

Since the axis of astigmatism is determined by the orientation of the least clear line (5-11), you can calculate its angle. The 5-11 line crosses horizontally and represents an axis of approximately 30 degrees