The short answer: Replace your glasses when your prescription changes, when the lenses are scratched or the coating is failing, or when the frame no longer holds a fit. Prescriptions usually expire after one to two years, so that is the first thing to check. If you squint, get headaches, or the lenses look cloudy and marked, it is time.

Your prescription changed

The most common reason is a new prescription. Vision drifts over time, so a two-year-old lens can leave you squinting or tired. Book an eye exam on schedule, and when the number changes, new lenses follow. You can keep the frame if you like it and it still fits, since many frames take fresh lenses.

The lenses are worn

• Deep or clustered scratches. They scatter light and tire your eyes, and they cannot be polished out.
• Failing coating. An anti-reflective or scratch coat that has crazed, clouded, or peeled clouds your view.
• Persistent haze. A film that will not clean off usually means the coating is going.

For how to clean them safely and stretch their life, see cleaning without scratching.

The frame no longer fits

A frame that will not stay adjusted has reached the end. Stretched temples, a stripped hinge, a cracked rim, or a bridge that keeps sliding all mean the fit is gone. Some of this you can fix at home, covered in tightening loose glasses, but a warped or cracked frame needs replacing, not repairing.

A note on sunglasses

Sunglasses follow the same rules plus one: UV protection can fade with years of sun and heat, and a scratched or coated-out lens lets glare and UV through. We cover that in do sunglasses expire. If in doubt about UV, an optical shop can test a lens in seconds.

From our test bench. We see two habits that cost people. They stretch a two-year prescription to four and blame new frames for feeling off, and they keep scratched lenses because the frame still looks fine. Check the prescription date first, then the lenses, then the frame. Any one of the three failing is reason enough to replace.

FAQ

How often should you replace your glasses?

Whenever your prescription changes, usually every one to two years, or sooner if the lenses are scratched, the coating is failing, or the frame no longer holds a fit.

Do I need new frames or just new lenses?

If the frame still fits and you like it, you can usually keep it and fit fresh lenses. Replace the frame when it is warped, cracked, or will not stay adjusted.

Can scratched lenses be repaired?

No. Deep scratches cannot be polished out and scatter light into your eyes. Replace the lenses when scratches sit in your line of sight.

Part of The Eyewear Care Manual · Related: do sunglasses expire · Browse eyeglasses · Last updated: August 5, 2026