The terms [PWR](Power), [SPH](Sphere) and [D](Dioptre) represent the visual correction power such as -1.00, -7.50 and -9.00.
As the magnitude of the number gets higher, the visual correction gets stronger.
For nearsightedness, it is represented by a negative sign (-) and for farsightedness, it is represented by a positive sign (+).
The visual power 0.00 is available on coloured lenses for customers who don’t need correction.