Keeping your glasses prescription accurate is more important than you might think. It’s not just about seeing clearly—it’s about giving your optometrist the chance to monitor your eyes and any changes. During a regular eye exam, we can check for signs of underlying problems, then update your prescription to keep your vision clear.
Glasses prescriptions are typically valid for 1–2 years. However, several factors can shorten or extend that timeframe. If you ever notice blurriness, strain, or headaches, it’s time to update your prescription and schedule your next eye exam.
What Your Glasses Prescription Includes
Your glasses prescription is more than just a series of numbers. It’s a detailed breakdown of the adjustments needed to correct your vision. Here’s what you’ll find in most prescriptions:
- OD (Oculus Dexter) & OS (Oculus Sinister) refer to your right and left eyes, respectively.
- SPH (Sphere), CYL (Cylinder), and Axis describe adjustments for nearsightedness, farsightedness, or astigmatism.
- ADD specifies any extra power needed for near vision, like for reading.
Your optometrist also includes their information, the dates your prescription was issued, and when your prescription expires. This document is essential for crafting lenses designed to give you clear vision.
How Long Glasses Prescriptions Typically Last
Over the years, your eyes undergo significant changes. Sometimes, medical and environmental factors come into play. Even your lifestyle can affect the lifespan of your glasses.
Typically, you can follow these guidelines:
- Glasses prescriptions for adults often last one to two years, depending on your eye care provider’s recommendation and your specific needs.
- For children and teenagers, prescriptions might need to be updated more frequently, typically every year, as their eyes are still developing.
- Certain medical conditions, like diabetes or rapid vision changes, may require more frequent check-ups and updates to the prescription.
Your eyes change as you grow, age, or encounter new health conditions. That’s why regular eye exams are so important—they help you stay ahead of potential problems and changes so you can keep your vision clear.
What Can Make a Glasses Prescription Change?
The typical lifespan of a prescription depends on factors such as:
- Age-related vision changes
- Developing medical conditions
- Increased screen time
- Changes in visual habits or needs
- Diet and lifestyle
- Your maintenance routine
- The make of the frames and lenses
Even if your prescription is still valid, these factors can change the effectiveness of your glasses.
How Often Should You Book an Eye Exam?
Routine eye exams are one of the simplest ways to maintain your eye health. They do more than just check if your prescription is up to date. These visits are designed to catch vision changes and detect underlying issues that could otherwise affect your sight and health.
Try to follow these guidelines:
- Children should have their first eye exam between 6 and 9 months.
- Children aged 2 to 5 years should have at least 1 eye exam before starting school.
- Children aged 6 to 18 years should have an eye exam annually.
- Adults aged 19 to 64 years should have an eye exam at least every 2 years.
- Adults aged 65 and older should have 1 eye exam annually.
Regular exams also make sure your glasses or contact lenses provide the correction you need. If you’re overdue for one, consider scheduling it sooner rather than later.

The Difference Between Glasses & Contact Lens Prescriptions
If you rely on both glasses and contacts, you’ve probably noticed that your prescriptions tend to look similar—but a little different, too. That’s because they each serve distinct purposes.
Glasses prescriptions account for lenses that are positioned about 12 millimetres away from your eyes. They’re designed to adjust light from a further distance from the eye.
Meanwhile, contact lenses rest directly on the surface of your eyes, so they require more specific details, such as the lens material, base curve, and diameter. The differences in these prescriptions make sure each lens works effectively while keeping your eyes more comfortable.
Signs It’s Time to Update Your Prescription
Sometimes life reminds us that our prescription may no longer be accurate. Here are a few signs it’s time to update your glasses prescription:
- Frequent headaches or eye strain
- Difficulty reading small text or seeing distant objects
- Squinting to see clearly
- Blurry or distorted vision
- Feeling like your current glasses or contacts aren’t as effective
- Experiencing any discomfort while wearing your lenses
These symptoms aren’t just annoying. They’re also signs that your eyes are asking for your attention. Your glasses and contacts should be comfortable, not irritating, so if you recognize these signs, visit your optometrist for your next eye exam.
Is It Time to Update Your Prescription?
Booking regular exams isn’t just about updating your glasses. It’s about prioritizing your eye health. When your prescription is current, life simply feels easier. Your eyes are comfortable, your vision is clear, and daily activities can be performed more smoothly. So, make sure to book your next eye exam with our team at Visionary Eye Centre! We’re committed to helping you step into a clearer, more comfortable future. You deserve clear and comfortable vision, after all!