Your Prescription Explained

Sample Prescription

R: +2.00/-0.75 X 90 ADD: +1.50

L: +2.50/-1.50 X180 ADD: +1.50

Sph (sphere)

The spherical part of your prescription, can be a plus or minus value.

A plus (+) indicates that you are long-sighted, which means objects close to you are difficult to see without your glasses.

A minus (-) indicates that you are short-sighted, which means you have difficulty seeing objects further away without your glasses.

The prescription numbers go up in 0.25 steps and they can be small like 1.00 or very high like 12.00. The higher the number on your prescription, the stronger the lenses required to correct your vision.

Cyl (cylinder)

The cylinder part of your prescription refers to the possible astigmatism you may have. This is normally presented in a minus format. If you have an irregular shaped cornea (the front surface of your eye), this is referred to as astigmatism. The higher this number, the more rugby ball shaped your cornea is. If this space is left empty on your prescription, this means your eyes are perfectly spherical.

Axis

The Axis measurement shown after your CYL (cylinder) power indicates the degrees and direction of the astigmatism.

Prism

If there is a muscle imbalance between your eyes, they don’t work well together, which can affect the quality of your vision and your depth of perception. It is possible that this may also cause you to suffer from double vision or headaches. Our optometrist test your eyes for any imbalance and then determine whether prism is required in your lens prescription to help your eyes work well together.

ADD

If your prescription shows a number in the ADD box, this indicates that you need further help to see clearly for reading and using the computer, or doing any close work. This may mean that you need another prescription or you may choose to have varifocal lenses.

If you have any further questions about your prescription, please feel free to ask our opticians in person, or visit ‘Ask Harry’ on our website to message us and we’ll get back to you.