שאלה משלב א׳ במחלות עיניים · מועד 2026, שאלה 12

For the cross cylinder the target should be one or two lines LARGER than the best acuity achieved with the sphere, so that the patient can see both positions of the flip and judge which is less blurred; using a line at the acuity limit makes both choices equally illegible. The duochrome target is for refining the sphere and the astigmatic dial is an alternative method of finding the axis before the cylinder power is checked.

מקור: Kanski p. 3 177