Why does my prescription look totally different from my last prescription, even though I was told there was no change?

There are two different ways to write a prescription, one is called ‘in minus cyl’ and the other is called ‘in plus cyl’, this means that two prescriptions can look totally different, but when transposed by a qualified Optician it can be exactly the same. Some Optometrists write their prescriptions using one method and others can write them using the other method.