You should have been given a form by your optician, with details of your prescription, including both right and left eye details. Below is an example of a standar NHS prescription form.
Click on the image to enlarge.
The prescription form on the Valley Optics website roughly mirrors the standard prescription form, making it easy for you to enter your prescription on our website.
Should you have any difficulties entering your prescription please call us on 08452 666 520.
Please ensure you copy your prescription as accurately as possible, paying particular attention to + and -. Occasionally Plano, PL or infinity may be written on a prescription. This means 0.
Your prescription can be broken down into 6 sections:-
Sphere. This part corrects your long or short sightedness. + lenses for long sightedness, - for short sighted lenses. The sphere is measured in quarter unit (Dioptre) steps, ie +0.25, +0.50, +0.75 etc.
Cylinder (Cyl). This corrects your astigmatism. An astigmatic eye has slightly irregular curvature. Imagine holding a tennis ball with no pressure. It is perfectly spherical. If you slightly squeeze it, it becomes slightly more curved one way than the other. (It is not, as some people describe it, a rugby ball shaped eye). The cylinder is also measured in quarter Dioptre steps, and can also be + or -. DS may be written in this box to denote no cylinder power.
Axis. This is the orientation of the cylinder. If your prescription has a cylinder, it must have an axis. Measured in degrees.
Add. This is the extra spherical power needed to change a distance prescription into a reading one. Always +, and almost always the same for both eyes. Measured in quarter Dioptre steps, usually no higher than +3.50.
Prism. This is rarely used, but prisms help correct muscle balance issues affecting focusing. Measured in Prism Dioptres, they go in quarter steps, are always +ve and usually do not go above 4. A prismatic lens will be slightly wedge shaped.
Base. This is the orientation of the prism. All prisms have a base, and will be either In, Out, Up or Down.
Pupillary Distance (PD)
This is the distance between the centre of your pupils when you are looking straight ahead. It should match the distance apart of the centre of the lenses in your glasses to prevent any unwanted problems.
The pd has to be taken during your eye test, but your optometrist does not have to put it on your prescription.