There are two separate clocks on every lens and they get confused constantly. One is how long the lens lasts before you throw it away. The other is how many hours a day it can safely sit on your eye. They are not related.
The replacement clock
Daily — worn once and binned. Nothing to clean, nothing to store. The safest option and the most expensive per wear.
Monthly — replace roughly 30 days after you first open the blister, not 30 wears. The clock starts on opening, because that is when the lens begins interacting with air and solution.
Yearly — this is the one people get wrong. Yearly means the lens is replaceable after a year of correct storage. It does not mean you can wear the same lens for a year, and it does not mean it survives twelve months of careless handling. Most yearly lenses are finished well before their date because the solution was topped up instead of changed.
The daily-wear clock
Separate from all of the above:
- Day one: eight hours maximum, even if they feel completely comfortable. Your cornea gets its oxygen from the air, and a lens reduces that supply. Tolerance has to build.
- After the first week: up to 10 hours for a standard hydrogel lens.
- Higher-oxygen lenses — Urban Layer in our range — hold comfort past 14 hours. That is a genuine material difference, not marketing.
- Never overnight. Closed eyelids cut oxygen further, and that combination is what turns irritation into infection.
Signs to stop immediately
Redness that does not clear within an hour of removal. Pain rather than dryness. Blurred vision that persists. Light sensitivity. Any discharge.
Take the lens out, leave it out, and if it has not resolved in a few hours, see an optometrist. There is no shade worth an eye.
Storage, briefly
Fresh solution every single night — pour the old out, do not top it up. Rinse the case with solution and air-dry it face-down. Replace the case every three months; it grows biofilm long before it looks dirty.
