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    Wearing guide

    Right and left lenses mixed up

    Your two scleral lenses are made for two different eyes. Here's how to tell if they've been swapped, and how to make sure it doesn't happen.

    By the Scleral Lens Team · Updated October 2, 2026 · 1 published source cited

    The short answer

    If both eyes are suddenly blurry or one lens feels wrong, the lenses may be in the wrong eyes. Take them both out, swap them, and do the three checks. To prevent it: always do the same eye first, and keep each lens in its own marked side of the case.

    Before you start

    Time: A few minutes.

    • Your removal plunger and inserter
    • Fresh preservative-free saline
    • Your lens case, with R and L clearly marked

    Step by step

    1. Take both lenses out

      Remove each lens over a towel, one at a time.

    2. Keep track of which is which

      Put the lens from your right eye in the left side of the case, and the lens from your left eye in the right side, so they're now where they belong.

    3. Rinse and refill

      Rinse each lens with preservative-free saline and fill to the brim from a fresh vial.

    4. Reinsert, right lens in the right eye

      Start with your usual first eye.

    5. Do the three checks

      Light, vision, comfort. Vision should now be clear in each eye.

    These are general steps. If your fitter taught you differently, follow your fitter: your lens and eyes are theirs to know. Print the mirror cards to keep by your sink.

    Habits that prevent mix-ups

    • Same eye first, every time. In and out. A fixed order is the simplest protection there is.
    • One lens out of the case at a time. Finish one eye before you pick up the other lens.
    • A clearly marked case. R and L you can read without your glasses, or different cap colors.
    • Know your lens markings. Ask your fitter whether your lenses have a marking that tells them apart, and what it looks like.

    A new case doesn’t change the rule

    When you replace your case, which the FDA advises doing every three months,[1] check that the new one is marked the same way before you put your lenses in it.

    Common mistakes

    • Taking lenses out in a different order on different days.
    • Using a case without clear R and L markings.
    • Leaving both lenses out on the counter at the same time.

    Common questions

    Can wearing the wrong lens hurt my eye?

    Usually it just makes vision blurry and the lens uncomfortable, because each lens is shaped for one eye. Take the lenses out and swap them. If your eye is painful or stays red, call your fitter.

    How can I tell my lenses apart?

    Ask your fitter. Some lenses carry a small marking, and your fitter can tell you what to look for on yours. A case with clearly marked sides, and always handling the same eye first, do most of the work.

    My two lenses have the same prescription. Does it still matter?

    Yes. Even with the same power, each lens is fitted to the shape of one eye, so swapping them can change how it fits and feels.

    Keep going

    Guide

    Blurry right after insertion

    Check for a bubble first: shine a light and look in the mirror. Then make sure the right lens is in the right eye, and look for film, smudges, or specks on the lens. Most of the time, removing the lens, cleaning or rinsing it, refilling to the brim, and reinserting fixes it.

    Guide

    The scleral lens daily routine

    Mornings: wash your hands, inspect and rinse the lenses, fill with preservative-free saline, insert, and empty and air-dry the case. Nights: remove over a towel, rub each side with your cleaner, and store in fresh solution, never topping off. Replace your case every three months.

    Sources

    1. U.S. Food and Drug Administration. Contact Lens Solutions and Products. fda.gov

    Last updated October 2, 2026. Found an error or a newer study? Let us know and we'll correct the page.