How to Read your Prescription

What do OS and OD mean?

Most opticians will write ‘left eye’ or ‘right eye’ when writing the prescription for each eye, but the terms ‘OS’ and ‘OD’ can also be used. OD is referring to your right eye, and OS is referring to your left eye.

 What is a Sphere (SPH)?

The first thing that will probably be written on your prescription is the ‘SPH’ or ‘sphere’. There should be one for each eye. The SPH is the correction for long or short-sightedness. The number will be written in .25 steps and will be preceded by a plus (+) or minus (-) sign.

A plus in front of the number indicates long-sightedness, which is called hyperopic, and is when someone has difficulty focusing on close objects. A minus sign indicates short-sightedness, called myopia, and is when a person has trouble focusing on distant objects. This number will sometimes be 0.00 which indicates there is no long or shortsightedness issue with the eye.

When ordering online it is important to make sure you have entered the correct plus or minus, as getting these mixed up will cause the glasses to make your vision worse and they will have to be replaced. Please double-check whether your prescription is plus or minus and enter it correctly. Each eye may have a different number, and one may even be longsighted while the other may be shortsighted.

What are the CYL and AXIS?

Next is usually the ‘CYL’ or ‘cylinder’, as well as ‘AXIS’. This refers to those with astigmatism when the eye is shaped slightly more like a rugby ball and less like a perfectly spherical football. The eye is called toric in this instance. The CYL refers to how bad the astigmatism is, and again goes up in 0.25 increments and can be either plus (+) or minus (-), so please make sure you double-check this is correct. The axis refers to what angle astigmatism lies, ranging from 0 to 180. This can go up in 1/2 measurements so please contact us directly if yours does so.

How do I add my prescription at GOTD Eyewear?

At GOTD Eyewear you can add your prescription to our premium optical glasses and sunglasses. It may be strange to add your prescription to an online optician but our step by step checkout makes it easy. Once you have chosen your frame,  choose the relevant coatings and tints to your glasses. Remember choosing your lens type along with coatings are made to suit your lifestyle, to personalise your glasses to your individual choice. You can learn more about the specific lens options we offer by clicking the 'lens options' tab next to the frame images. After choosing your lenses you can then add your prescription using our step by step form. Simply fill in all the sections which are available on your prescription for the GOTD Optometrist to inspect. Still unsure? Send a photo of your prescription to the GOTD Optometrist and she'll ensure your glasses are made up correctly. Don't forget to add your initials for your free personalised glasses case!

If you have any questions, the GOTD Optometrist will be happy to help and you can contact her here