Patients often ask, “Why can’t I just order these like regular soft contacts?” The answer is that fitting a scleral or RGP (rigid gas permeable) lens is a medical procedure, and the eye needs to adapt to each version of the lens during the fitting process. A 3-4 month timeline is common, and for complex cases, it can be longer.
The Fitting Process is a Series of Revisions
Unlike a soft lens that drapes, a scleral lens is a rigid structure that must vault the cornea perfectly without touching it, while sealing comfortably on the sclera.
Month 1: The Initial Fit & First Revisions
- Visit 1 (1- 2 hours): Mapping your cornea, choosing the initial lens diameter and vault.
- Visit 2 (1-2 weeks later): You try the first lens. The doctor evaluates “edge lift,” “central clearance,” and “landing zone alignment.” Usually, it’s not perfect- yet. They order a first revision (e.g., steeper periphery, more vault). This takes 1-4 weeks for the lab to make, depending on which type of lens you have.
Month 2: Adapting to the Lens & Refining Optics
- Adaptation Period: Rigid lenses feel strange at first. It takes 1-2 weeks, sometimes more, of gradually increasing wear time for your eyelids, vision, and nerves to adapt. Neurology can’t be rushed, unfortunately.
- Adding Complexity (The Biggest Time Factor): Adding multifocal or Higher Order Aberration (HOA) correction to lenses increases the amount of lens revisions in a fitting. We must align the lens’s optical center with your pupil and the aberration pattern. If it’s off by 0.5mm, vision is blurry. That requires a second lens revision (another 2-4 weeks, depending on lens type).
Month 3-4: Finalizing & Verifying
- Over-Refraction: Once the fit is comfortable and stable, the doctor performs an “over-refraction” (placing glasses over the lens). This fine-tunes the power. For HOA lenses, they may use a wavefront aberrometer to measure the remaining aberrations.
- The “Wear & See” Test: Patients often take the last few versions of lenses home for 1-2 weeks to see what is best for them —driving at night, working on computers, etc. If you see halos or have edge discomfort, another revision is needed.
Important Exceptions to the Timeline
- Refitting lenses from an existing design is generally faster than starting a lens design from scratch: If you already have a working design (e.g., your first scleral fitting) and just need a new one due to minor Rx change, that refit might take only 1-2 months.
- Simple RGP: A basic spherical RGP on a healthy eye might take 6-8 weeks.
- Impression-based Lenses: These can sometimes be faster in the final fit because the mold eliminates most fitting guesswork, but the initial impression and lab fabrication add time upfront.
The bottom line: Those 3-4 months are an investment in the best lens fit and vision possible. Each revision is a step closer to a lens that gives you your clearest achievable vision without pain or dryness.
Good things take time!
