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    Question

    What is PROSE treatment?

    PROSE stands for Prosthetic Replacement of the Ocular Surface Ecosystem. It's a scleral lens treatment developed by BostonSight. Here's what makes it different and what the research shows.

    By the Scleral Lens Team · Last reviewed October 2, 2026 · 7 published sources cited

    The short answer

    PROSE is a customized scleral lens treatment from BostonSight, based in Needham, Massachusetts. The device itself is a scleral lens: a gas permeable dome filled with saline that vaults over the cornea and rests on the white of the eye. What sets PROSE apart is its proprietary design software and a structured treatment program with intensive training. It's mainly used for people with severe ocular surface disease or irregular corneas who haven't done well with other options.

    Key points

    • A PROSE device is a scleral lens; one 2025 review describes scleral lenses and PROSE as the same type of device.
    • Each device is designed with BostonSight's own software and adjusted over a treatment window that can last months.
    • Studies report better vision and fewer symptoms for many people, mostly from single centers and retrospective chart reviews.
    • Corneal swelling is a known limitation, especially in eyes with a weak corneal endothelium.

    What PROSE is

    PROSE stands for Prosthetic Replacement of the Ocular Surface Ecosystem. It was developed at BostonSight in Needham, Massachusetts. BostonSight’s own clinicians describe the device as a transparent dome of gas permeable plastic, 13 to 23 mm across, that fits under the eyelids, rests on the conjunctiva over the sclera, and is filled with preservative-free saline before it goes in.[1] That is the same basic idea as any scleral lens. A 2025 review goes further and calls scleral lenses and PROSE the same device, with PROSE serving both optical and therapeutic purposes.[3]

    What’s distinctive is the process around the device:

    • Proprietary design. Each device is customized to the eye using BostonSight’s web-based design software, which drives the manufacturing lathe.[1]
    • A defined treatment window. At BostonSight, PROSE treatment runs over a six-month window during which the device can be adjusted until the fit and comfort are right.[1]
    • Structured training. Treatment includes fitting, intensive training to apply and remove the device, care instruction, and monitoring.[1]

    BostonSight-affiliated authors describe PROSE as an FDA-approved, highly customized scleral lens treatment used for conditions such as dry eye disease, ocular graft-versus-host disease, neurotrophic keratitis, and Stevens-Johnson syndrome.[2] It’s also used for irregular corneas such as keratoconus and corneas after a transplant.[4]

    Who it’s usually for

    People referred for PROSE at BostonSight have generally not done well with other treatments, so as a group they tend to have more severe disease.[1] If you’ve struggled with standard scleral lenses, PROSE is one option to ask about, alongside a refit with a different design or an impression-based lens.

    What the studies show

    Most PROSE research comes from single centers and looks back at patient charts. That’s useful, but it can’t show how PROSE compares with other scleral lenses head to head.

    • Vision. At a Canadian PROSE center, 126 eyes of 78 patients gained an average of about four lines on the eye chart. Eyes with distorted corneas gained more than eyes with ocular surface disease.[4]
    • Graft-versus-host disease. In 79 eyes of 40 patients, 90% had better vision with PROSE. Among the 29 patients still available at follow-up, average symptom scores on a dry eye questionnaire fell from 72.6 to 21.1.[5]
    • Symptoms across conditions. At BostonSight, 134 patients started treatment and 43 completed a follow-up symptom survey. In those 43, average scores improved by about 55%. The authors are BostonSight employees.[1]
    • Children with Stevens-Johnson syndrome. In 49 children treated at one center over 25 years, median vision improved from about 20/80 to 20/30, and 30.6% of patients did not succeed with treatment.[6]

    Where PROSE falls short

    PROSE carries the same core limitations as other scleral lenses. At one center, 8 of 125 eyes (6.4%) failed treatment, and 6 of those 8 failed because of worsening corneal swelling. Eyes with risk factors for a weak endothelium, such as Fuchs’ dystrophy or a previous full-thickness transplant, failed more often: 22.2% compared with 1.6%.[7] Two eyes stopped because debris built up behind the device and blurred vision.[7]

    Access can be the other limit. Ask where PROSE is offered and how many visits the program involves, since it may mean travel. A skilled local scleral lens fitter may be able to offer a custom scleral lens closer to home. For more on corneal swelling, see do scleral lenses change the shape of your cornea?

    Common questions

    Is PROSE better than a regular scleral lens?

    There isn't good evidence to say one is better in general. PROSE devices are scleral lenses designed with BostonSight's own system and delivered through a structured program. Many people referred for PROSE have already struggled with other lenses, so results from PROSE studies describe a harder-to-treat group. The skill of the fitter and the fit on your eye matter more than the brand.

    Where can I get PROSE?

    Ask BostonSight or your eye doctor where PROSE is currently offered near you. If it isn't close by, ask whether a local fitter offers a custom scleral lens for your condition.

    Is PROSE covered by insurance?

    Coverage varies by plan. Ask the provider how the treatment will be billed and which codes they'll use, then check with your plan before starting. Our insurance guides list the questions to ask.

    Keep reading

    What are mini-scleral lenses?

    A mini-scleral lens is a scleral lens that extends only a little past the edge of your cornea. In the classification most often cited, a mini-scleral lens is up to 6 mm wider than the visible colored part of your eye, and a large scleral lens is more than 6 mm wider. Both vault over the cornea and rest on the white of the eye; they just differ in how far they reach. Your fitter picks the size that suits your eye's shape and your condition.

    What are impression-based scleral lenses?

    An impression-based scleral lens is made from a physical mold of the front of your eye. The mold is scanned in 3D and a lens is cut to match its shape, including bumps or irregular areas on the white of the eye. EyePrintPRO is the best-known example. Studies from a few clinics report better vision and successful wear in many people who couldn't wear standard scleral lenses, though adverse symptoms and refits do occur.

    What is scleral profilometry?

    Scleral profilometry is an imaging scan that measures the height and shape of your cornea and the surrounding white of the eye. Fitters can use the map to design a scleral lens, including a landing zone shaped to match an uneven sclera. Studies so far show it can work, with fitting effort similar to traditional trial-lens fitting, but it doesn't replace a fitter's judgment. Most scleral lenses are still fitted with trial lenses.

    Do scleral lenses change the shape of your cornea?

    Scleral lenses are designed to vault over the cornea rather than press on it, so they aren't meant to reshape it. Studies find small, temporary changes: slight corneal swelling while the lens is on, and minor curvature changes that mostly return to baseline after the lens comes out. Eyes with a weakened inner corneal layer, such as after a transplant, can swell much more, so they need closer monitoring. Scleral lenses are not a treatment to stop keratoconus from progressing.

    Sources

    1. Asghari B, Brocks D, Carrasquillo KG, Crowley E. OSDI outcomes based on patient demographic and wear patterns in prosthetic replacement of the ocular surface ecosystem. Clin Optom (Auckl). 2022;14:1-12. doi:10.2147/OPTO.S337920 pubmed.ncbi.nlm.nih.gov
    2. Nakhla MN, Patel R, Crowley E, et al. Utilizing PROSE as a drug delivery device for preservative-free cyclosporine 0.05% for the treatment of dry eye disease: a pilot study. Clin Ophthalmol. 2024;18:3203-3213. doi:10.2147/OPTH.S487369 pubmed.ncbi.nlm.nih.gov
    3. Rodriguez-Garcia A, Jimenez-Perez JC, Ruiz-Lozano RE, et al. Scleral lenses and PROSE: indications, complications, and future challenges. Med Hypothesis Discov Innov Ophthalmol. 2025;14(3):73-106. doi:10.51329/mehdiophthal1525 pubmed.ncbi.nlm.nih.gov
    4. Wong BM, Garg A, Trinh T, et al. Diagnoses and outcomes of prosthetic replacement of the ocular surface ecosystem treatment: a Canadian experience. Eye Contact Lens. 2021;47(7):394-400. doi:10.1097/ICL.0000000000000779 pubmed.ncbi.nlm.nih.gov
    5. Theophanous C, Irvine JA, Parker P, Chiu GB. Use of prosthetic replacement of the ocular surface ecosystem scleral lenses in patients with ocular chronic graft-versus-host disease. Biol Blood Marrow Transplant. 2015;21(12):2180-2184. doi:10.1016/j.bbmt.2015.07.027 pubmed.ncbi.nlm.nih.gov
    6. Wang Y, Rao R, Jacobs DS, Saeed HN. Prosthetic replacement of the ocular surface ecosystem treatment for ocular surface disease in pediatric patients with Stevens-Johnson syndrome. Am J Ophthalmol. 2019;201:1-8. doi:10.1016/j.ajo.2019.01.006 pubmed.ncbi.nlm.nih.gov
    7. Schear MJ, Ibrahim K, Winokur J, et al. Treatment limitations with PROSE (prosthetic replacement of the ocular surface ecosystem): one center's experience. Eye Contact Lens. 2019;45(5):315-317. doi:10.1097/ICL.0000000000000610 pubmed.ncbi.nlm.nih.gov

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