the initial rk surgery additional strain introduced during the first months of healing usually necessitates slight lengthening of the existing incisions to new resistance points b or adding of a few new incisions as described above to reestablish the emmetropic condition in fig1 dotted lines 18 1 through 18 4 and points 18 5a b and 18 6a b represent incisions made in a cornea 10 to correct an astigmatism that is designated by dashed lines 28 a first incision 18 1 is begun at starting point a which is selected on the basis of the surgeon 39 s determination of the location of a suitable starting point the rk knife is moved in the direction tangential to the steepest slope portion of astigmatism 28 until a sudden increase in resistance is experienced at point b then a second incision 18 2 is made parallel to incision 18 1 continuing from its starting point a until a substantially increased resistance point b thereof is detected starting point a of incision 18 2 may be located approximately 1 millimeter from point a of first incision 18 1 as shown this procedure is repeated until a resistance point b of an incision coincides with the starting point a of that incision for example as indicated by incisions 18 5a b then the same procedure is repeated on the opposite side of astigmatism 28 to form incisions 18 3 18 4 and 18 6a b at which point strain has been eliminated or nearly eliminated in all of the fibrils associated with or causing astigmatism 28 although the results.