1. A method of calculating the required power of a toric ophthalmic implant, comprising the steps of: a) determining an optimum cylindrical refraction needed to correct sphero-cylindrical refractive errors in a patient's eye; b) calculating a predicted surgically induced refractive change to the patient's eye; and c) analyzing the optimum cylindrical refraction needed to correct sphero-cylindrical refractive errors in the patient's eye in combination with the predicted surgically induced refractive change to the patient's eye to determine the required power of the toric ophthalmic implant.