A contact lens prescription for the correction of nearsighted astigmatism, for example, could be: -2.50 -1.00 x 90.
The first number (-2.50) stands for the Sphere power for the correction of myopia in the flatter (less nearsighted) part of the eye.
The second number (-1.00) stands for the Cylinder power of the additional myopia (nearsightedness) correction required for the more curved part of the eye. In this case, the total correction required for this area (also called meridian) is -3.50 D (-2.50 + -1.00 = -3.50 D)
The third number (90) is called the Axis. This is the location (in degrees) of the flatter area of the eye, on a 180-degree scale where 90 degrees designates the vertical axis of the eye, and 180 degrees designates the horizontal axis.
Optometrists in Dubai, Abu Dhabi, Riyadh and Jeddah will usually provide a complete rx prescription including sphere, cylinder, axis as well as base curve of the required lenses.