Will be having Toric IOLs for cataract lens exchange. After a corneal topography I was told my corneal astigmatism is 2.7cyl (LE) and 2.9cyl (RE). Just realized it is way different from my glasses RX cyl, which is -1.25cyl (LE) and -0.75cyl (RE). What is the difference between these two astigmatisms, shouldn't they be fairly similar?