Why topping up doesn’t work
A scleral lens rests on the white of the eye and vaults over the cornea. The space between the lens and your cornea is filled with saline when you insert it, and the edge sits snugly enough that very little tear fluid moves in and out. Researchers describing infections in scleral lens wearers noted this minimal tear exchange and the fluid reservoir as part of what makes these lenses different from other contact lenses.[1]
That seal is what keeps your cornea bathed in fluid all day. It’s also why you can’t easily add more:
- Drops over the lens stay on top. A rewetting drop lands on the front of the lens and on the white of your eye around it. It doesn’t get pulled under the lens to top up the bowl.
- Lifting the edge lets the wrong things in. Prying up the edge with a finger, plunger, or dropper tip to squeeze saline underneath tends to break the seal. Air, tear fluid, and whatever is on your lids are as likely to get in as the saline you’re adding. You may end up with a bigger bubble than you started with.
- It puts something near your eye that shouldn’t be there. A dropper tip, a vial edge, or a plunger next to the cornea can scratch the eye or contaminate the fluid.
Bubbles: remove, refill, reinsert
If you see a bubble after insertion, or your vision is blurry or shimmering in one spot, the fix wearers and fitters agree on is simple: take the lens out, refill it with fresh saline, and put it back in.
Bubbles over the center blur your vision. Wearers are also commonly told by their fitters not to leave a bubble in, because it can leave part of the eye without fluid and feeling dry or sore. If bubbles happen often, it’s usually technique, such as the lens tilting, under-filling, or pulling back at the last moment. See filling solution and air bubbles and blurry after insertion. If bubbles keep coming back however careful you are, tell your fitter.
Dryness or fog later in the day
Some wearers find the lens feels dry, the fluid behind it turns cloudy, or vision fogs a few hours into the day. Adding saline under the lens won’t fix any of these, because the problem is either debris building up in the fluid behind the lens or the front surface drying out. Many wearers make a midday remove, rinse, and refill part of their routine, and say it resets their comfort and clarity.
For the front of the lens, preservative-free rewetting drops approved by your fitter can help between refills. For haze behind the lens, the lens has to come out. See midday fogging and can you clean a scleral lens without taking it out?
Why fresh, sterile saline matters
The fluid behind your lens sits against your cornea for hours. A report on Acanthamoeba infections in scleral lens wearers suggested the reservoir could act as an environment for the organism to multiply, and recommended sterile saline, preferably single-use, among other care steps.[1] The FDA advises discarding leftover solution and never reusing lens solution.[2]
So each refill should be a new vial, filled into a clean, rinsed lens with clean, dry hands. Don’t save the rest of an opened vial for later, even later the same day.
Do
- Remove, rinse, and refill the lens when you see a bubble.
- Use a fresh, sterile vial for every fill.
- Use fitter-approved preservative-free drops over the lens if it feels dry.
- Carry a small kit so you can refill away from home.
Don’t
- Pry up the lens edge to squeeze saline underneath.
- Touch a dropper tip or vial to your eye or lens.
- Reuse an opened vial for a midday refill.
- Ignore a bubble that blurs vision or makes the eye sore.
What wearers say
Some wearers have tried dripping saline at the edge or lifting the lens slightly, and most say it either did nothing or made things worse. The common experience is that once a bubble is there, a quick removal and refill is faster than fighting it. Many carry a small pouch with saline, a case, and plungers so they can refill at work or in the car. A few wearers need midday refills only on dry, windy, or allergy days; others do one every day and treat it as routine.
What to ask your fitter
- I keep getting bubbles. Can you watch me insert and check the fit?
- Which rewetting drops can I use with my lenses in?
- My vision fogs by midday. Is the haze in front of or behind my lens?
- Is a midday remove and refill reasonable for me, and how often?
Common questions
Can a small bubble work its way out on its own?
Sometimes a tiny bubble at the edge moves around or seems to vanish, but you can't count on it. Bubbles over the center blur vision, and wearers are commonly told by fitters to remove and reinsert rather than wait, because a bubble can leave part of the cornea without fluid.
Do rewetting drops help with dryness while the lens is in?
They can help the front surface of the lens and the white of the eye around it feel better. They don't refill the fluid behind the lens. Use only drops your fitter has approved for use with lenses in, usually preservative-free.
When I take my lens out there's hardly any fluid left. Has it leaked?
The layer of fluid under a scleral lens is thin, and some drips out as the lens comes off, so a lens can look nearly empty at removal even when it was full of fluid. If the lens feels dry or vision changes during the day, mention it to your fitter.
Can I reuse the rest of my morning vial for a midday refill?
No. Single-use vials are meant to be used once and the rest thrown away. Open a fresh vial for each fill. The FDA advises never reusing lens solution.