Prescriptions

Your prescription is typically divided up into several measurements:

Sphere (Sph)

This can be a plus or a minus number and will end in two decimal places of .00, .25, .50, or .75. If no power is required in this field then this can be written as 0.00, Plano or sometimes the infinity symbol: . You may sometimes see the letters DS written after the numbers to indicate that there is no cylinder power required (see below)

Cylinder (Cyl)

This can be a plus or a minus number and will end in two decimal places of .00, .25, .50, or .75. If no power is required in this field then it can either be left blank or you may sometimes see the letters DS.

Axis.

This field will only be completed if there is an entry in the Cylinder field, and it will be a number between 0 and 180. Typically this will be a whole number, but will sometimes be a half number eg 77.5.

Add

This field will only be completed if you require a different prescription for close up activities such as reading, and will typically be between +0.50 and +3.50, but will occasionally be outside of this range upto a maximum of +5.00. This field indicates the amount of additional power that is required on top of your distance prescription to create your reading prescription.