About your prescription
Reading a prescription for glasses might seem complex, but with a few explanations, you will manage! Here is how to decipher the essential information from your prescription:
Understanding Your Prescription
| SPH | CYL | AXIS | ADD | PD | |
|---|---|---|---|---|---|
| OD (Right) | -2.00 | -0.50 | 180 | +1.50 | 30 |
| OS (Left) | -2.25 | -0.75 | 175 | +1.50 | 30 |
The numbers under SPH (sphere) represent the degree of myopia (expressed as a negative number) or hyperopia (expressed as a positive number). The higher the number, the stronger the optical correction so you will need thinned lenses with an index of 1.56, 1.59, 1.60, or 1.67.
The numbers under CYL (cylinder) define the value of astigmatism, and the AXIS (in degrees) specifies the orientation of this astigmatism.
The numbers under ADD (addition), expressed as a positive number, represent the degree of presbyopia. This addition is added to the distance prescription to correct near vision, usually for people aged 40 and over.
The PD (pupillary distance) represents the distance in millimeters between the centers of your pupils. Example: PD: 63. This measure, taken from the center of your nasal bridge, can give different values (2 PDs, right and left) e.g., PD 32-31, meaning the distance between your nasal bridge and your right eye is 32 mm, and to your left eye is 31 mm. This PD measure is used to align the optical center of each lens with the respective center of your eyes properly, allowing for clearer vision.
To order your glasses online, make sure you have a recent prescription from your optometrist (a valid prescription should not exceed two years).
Your prescription should include:
- The name of the optometrist, their license number, and their signature.
- Your full name.
- The date of the exam.
- The details of your full visual correction (distance vision and/or near vision).
Preferably, your prescription should include your PD (pupillary distance) measurement. If it does not include the PD measurement, you can obtain it from the vision professionals who previously made your glasses (this information in your record belongs to you and can be obtained upon request).
High-Index Lenses Explained
High-index lenses are thinner and more powerful, offering a lightweight, stylish solution for those with higher prescriptions. While most prescriptions can be matched with various indices, it's essential to choose the one that suits your needs best. The index of your lenses impacts appearance, comfort and vision. Regular lenses are affordable but suitable for lower prescriptions. Thinner lenses, on the other hand, are lightweight, contemporary and can accommodate a wider range of prescriptions, including higher ones.
Recommended Lens Index
| Lens Index | Features | SPH Range | CYL Range |
|---|---|---|---|
| 1.50 | Conventional plastic lenses. For light prescriptions. | -1.50 to +1.50 | 0 to -2.00 |
| 1.56 | Thinner and lighter than 1.50. For moderate prescriptions. | -1.25 to -4.00 / +1.25 to +4.00 | 0 to -2.00 |
| 1.59 | Impact-resistant Polycarbonate with UV protection. For moderately-strong prescriptions. | -2.25 to -6.00 / +2.25 to +6.00 | 0 to -4.00 |
| 1.60 | Extra thin and light. Great choice for stronger prescriptions. | -2.25 to -6.00 / +2.25 to +6.00 | 0 to -4.00 |
| 1.67 | Extremely thin and light. For extra-strong prescriptions. | -5.00 to -9.00 / +5.00 to +9.00 | 0 to -4.00 |
| 1.74 | As thin as possible for the strongest prescriptions. | +/-7.00 and above | 0 to -4.00 |
