Answer:
Actually, there is always iritis after cataract surgery. This is simply part of the natural healing response of the eye. Cataract surgeons grade this on a scale of "trace" to "4+." With the standard post-op drops this usually resolves completely by four to eight weeks after surgery. However, certain conditions (such as diabetes) can result in a longer course of inflammation.
Sometimes, however, the iris is damaged during cataract surgery. Iris trauma can result from conditions that affect the dilation of the pupil (such as pseudoexfoliation and use certain medications). Anyone taking Tamsulosin (aka Flomax) or drugs like it should tell their eye surgeon as these drugs are associated with a condition known as Intraoperative Floppy Iris Syndrom (IFIS) that can increase the risk of iris damage, capsular rupture, retinal detachment, etc. If the surgeon is made aware of the use of this drug before surgery, s/he can often take extra precautions to limit the risks during surgery.