Can your astigmatism prescription numbers change from-1.00 cyl and 105 axis to plus 1.00 cyl and 015 axis in 2 years?

Since nobody qualified has answered this, I will speculate. I AM NOT AN EXPERT. I think the change in sign and the shift of 90 degrees are equivalent, and some examiners prefer to write it one way and others write it the other way. Did your sphere also jump by about -1 in the same time? Astigmatism is basically one correction in one direction and a different correction at a right angle to that. This is usually written as the one correction and the difference to be applied to make the other correction. Sphere -1 cylinder -1 axis 105 adds up to -2 along the 105 degree direction, and -1 along the 15 degree direction. A prescription of sphere -2 cylinder +1 axis 15 also adds up to -2 along 105 degrees and -1 along 15 degrees.