<qa>  What is the difference in cylinder axis of less than 0.75D?- Eyes for which the baseline manifest subjective refraction exhibits a difference of greater than 0.75D in sphere power, or a difference of greater than 0.50D in cylinder power, or a difference in cylinder axis of more than 15 degrees compared to the baseline cycloplegic subjective refraction. For manifest cylinder of less than 0.75D, the difference in cylinder axis will not be taken into consideration. 