Your fitter sets the number
When you first get your lenses, your fitter gives you a starting number of hours and a plan for building up. They adjust it at your follow-up visits, after looking at how your eye handled the lens. Follow that plan even on days the lenses feel great. The step-by-step version is in our wearing schedule guide.
The FDA’s general advice for contact lens wearers is to follow the directions that come with your lenses and get regular eye exams.[7]
What studies of real wearers show
These numbers describe groups of people, not a target for you.
- A one-year study of 95 wearers found that people new to scleral lenses averaged 9.8 hours a day at one month and 11.1 hours a day at twelve months. Days of wear per week also rose, from 5.1 to 5.6.[1]
- A single-clinic review of 29 patients with difficult corneas, followed for an average of about four years, reported mean wear of 9.3 hours a day, with individuals ranging from 2 to 16 hours.[2]
- A three-month study of 32 patients fitted with smaller (mini-scleral) lenses for corneal irregularity reported an average of 12.1 hours a day.[3]
So a typical full day of wear is common, but the range is wide. Short wear time isn’t a failure. Some people need fewer hours, and some choose to wear glasses for part of the day.
Why comfort isn’t the guide
A scleral lens vaults over the cornea and rests on the white of the eye, so it can feel comfortable for a long time. That’s part of the appeal. But some effects of wear, such as corneal swelling, aren’t something you can feel. A review of how fitters assess scleral lenses notes that a lens that vaults too high can reduce oxygen to the cornea and cause swelling in people whose corneas are more vulnerable.[6] Your fitter checks for this at visits, which is one reason your limit comes from them.
Midday breaks can help
Some wearers find their vision gets foggy partway through the day. In a study of 120 veterans who wore scleral lenses, 15.8% reported midday fogging or bubbles.[5] A planned midday removal, rinse, and refill with fresh saline can help with this.[6]
Breaks may also help with total wear time. In a review of 97 patients with irregular corneas, those who took brief breaks every 4 to 5 hours of continuous wear to refill their lenses had a significantly higher success rate.[4] That was a single-center, retrospective study, so it shows an association, not proof. Ask your fitter whether a midday break suits you, and keep the supplies you need with you. See the emergency kit guide.
Signs you’ve worn them too long today
Take the lenses out and switch to glasses if your vision gets foggy and a refill doesn’t fix it, if your eye starts to ache or feel tight, or if you notice redness building around the edge of the lens. Mention it at your next visit, since it may mean the fit or your schedule needs adjusting.
Common questions
Can I wear scleral lenses for 16 hours?
Some people do. In one clinic's records, individual wearers ranged from 2 to 16 hours a day. Whether a long day is right for you is your fitter's decision, based on how your cornea looks after a full day of wear.
Why did my fitter give me a lower limit than my friend's?
Limits depend on your eyes, not on an average. A cornea that is more prone to swelling, for example, may need a shorter day. Ask your fitter what would need to change for your limit to go up.
Does taking the lens out at lunch reset the clock?
Not necessarily. A midday removal and refill can help with fogging and comfort, and one study linked breaks to more successful wear, but your total daily limit still comes from your fitter. Ask them how breaks fit into your schedule.