When you have your eye's tested your optician is required by law to give you a written copy of your prescription. Most written prescriptions follow a specific format which will look something like this:
Here you can see that the prescription has a "Right eye" a "Left eye" and then "Sph", "Cyl" and "Axis" for each with values written in the relevant boxes. There is also a "Near" part which sometimes is referred to as the "ADD" or "Addition" this is the "Addition" to your Distance prescription to ascertain your Reading Prescription and the value is always the same for both your right eye and left eye.
When you have decided on a pair of glasses and you are asked for your prescription simply select the correct values for each box paying particular attention to the "+" and "-" fields for example if you enter +4.25 and your prescription says -4.25 your lenses will be incorrect. Here you can see the above prescription as it would look once entered correctly into our web site:
You may also notice the PD section this is the distance between your pupils in millimeters. Your optician may or may not give you this information, the optician is also not required to do so as part of your eye test. If the PD is left to default we will calculate your Average PD based on your order information such as the size of frame, your gender and age. If you would like to measure your own PD get a friend to help you, focus on a fixed point in the distance whilst your friend measures the distance between the centre of one pupil to the centre of the other in millimeters. Remember help with your prescription is available free on 0800 169 1734.