Quick answer: There's no fixed expiry. Replace them when the lenses get scratched, the coating wears off, or the frame loosens, roughly every 1-3 years with normal use. The blue-light filtering itself doesn't wear out, but scratches and coating damage reduce comfort and performance.
Replace them when
- The lenses are visibly scratched or hazy
- The coating is peeling, patchy, or flaking
- The frames are loose, bent, or no longer fit well
- Your vision needs change, get an eye exam if so
Make them last longer
- Clean them properly, rinse first, then a microfiber cloth (never your shirt or paper)
- Store them in a case, not face-down on a desk
- Take them off with two hands so the frame doesn't warp
- Keep them out of heat, like a hot dashboard
The bottom line: Blue light glasses don't expire on a schedule, replace them when scratches, coating wear, or a loose frame start to bug you, usually every 1-3 years. Good cleaning and storage stretch that out.
