To correct high astigmatism, cataract surgeons may combine limbal relaxing incisions (LRIs) with toric IOL use. LRIs produce a coupling effect, in which the amount of flattening that occurs in the incised meridian is nearly equal to the amount of steepening that occurs 90 degrees away, with little resulting change in spheroequivalent. This obviates the need to make any change in implant power. More