My questions are as follows
1) Can an astigmatism be too slight to correct with lasik when you are farsighted?
2) Can an astigmatism resolve on it's own if you are corrected for farsightedness?
3) when an astigmatism is induced by a laser is usually irregular or regular?
Thank you for your time and patience, Tracy

AStigmatism can be very slight (0.25 diopters), and in these situations, the laser generally is not programmed to treat this level of astigmatism. This tiny amount of astigmatism is generally not visually significant.
As far as postop, it is certainly possible that as the eye heals, any residual astigmatism can become less or more. There is no way to predict for a single person, but in general, most of the astigmatism that is programmed into the laser is successfully removed.
Of course, it is possible that even if the laser is programmed to remove astigmatism, that some residual astigmatism will remain. This is typically regular astigmatism. Of course, irregular astigmatism can also develop (and this is not currently treatable with additional laser).

I hope this helps

Bill Trattler,MD
Miami,FL

PS:Dr.Hu's old post is indeed old. both the VISX and Autonomous lasers are approved to treat hyperopic astigmatism.