Understanding your prescription

When it comes to understanding your eye prescription, here are some important points to know:

1. Components of the Prescription: An eye prescription typically includes several measurements:

   • Sphere (SPH): Indicates the lens power needed to correct nearsightedness (negative number) or farsightedness (positive number).
   • Cylinder (CYL): Measures astigmatism, which affects how light enters the eye. This value can also be positive or negative.
   • Axis: A number between 1 and 180 that shows the orientation of the cylinder in degrees.
   • Addition (ADD): If you need multifocal lenses (like bifocals), this indicates the additional magnifying power for reading.

An eye prescription may include any of the following abbreviations:

• OD: oculus dexter (right eye)
• OS: oculus sinister (left eye)
• OU: oculus uterque (both eyes)
• SPH: the strength of magnification in the lenses
• CYL: cylindrical correction, or the amount of lens power needed to correct astigmatism
• AXIS: indicates the angle of astigmatism correction
• ADD: addition, used for bifocal and multifocal lenses

 

• Mild +/-0.25 to +/-2.00 
• Moderate +/-2.25 to +/- 5.00
• Severe +/- 5.00

 

 

1. Pupillary Distance (PD): This measurement is crucial for properly aligning lenses with your pupils. It can be measured in millimeters and is often included on the prescription.

2. Validity Period: Eye prescriptions usually have a validity period, often ranging from one to two years. After this, a new exam may be required to ensure your vision hasn't changed.

3. Importance of Regular Check-Ups: Regular eye exams are essential, even if you think your vision hasn't changed. They can detect underlying health issues as well.

4. Understanding Your Needs: Different activities (like reading, computer use, or driving) may require different types of lenses. Discuss your lifestyle with your eye care professional to get the best fit.

When customizing your lens consider your everyday lifestyle and choose the options for your style, comfort and visual needs.

 

Lens Thickness

1. Weight and Comfort: Thicker lenses can be heavier, which may cause discomfort, especially for stronger prescriptions. Knowing the thickness helps you choose lenses that are comfortable to wear throughout the day.

2. Aesthetic Considerations: Thinner lenses often look more attractive, especially in fashionable frames. If you prefer a sleek appearance, opting for thinner lenses can enhance the overall look of your glasses.

3. Durability: Thicker lenses may be more resistant to scratches or impacts, but advancements in lens materials mean that many thinner lenses are also quite durable. Understanding the trade-offs can help you choose what fits your lifestyle.

Lens Enhancements

1. Functionality: Lens enhancements like anti-reflective coatings, blue light filtering, or photochromic properties (transition lenses) can significantly improve your visual comfort and quality. Knowing these options allows you to select lenses tailored to your needs.

2. Protection: Some enhancements provide additional protection against harmful UV rays or digital eye strain, which is increasingly important in today’s screen-heavy environment.

3. Performance in Different Conditions: Enhancements can improve vision in specific conditions, such as night driving (anti-glare) or outdoor activities (polarized lenses). Knowing the available enhancements helps you choose the best lenses for your activities.

Anti-fog lens treatment    

Anti glare/anti reflective lens treatment 

If you have questions about your prescription, please contact your eye doctor.

 

Addition resources: Your rights when buying prescription glasses: