Why the landing zone shows changes
A scleral lens is meant to vault the cornea and limbus and land evenly on conjunctiva over the sclera, without compression, impingement, or edge lift.[2] The sclera rarely makes that easy. Of 140 eyes mapped with a scleral topographer, only 5.7% had a primarily spherical sclera; 28.6% were regularly toric and the rest had asymmetric or irregular patterns, with the nasal sclera generally flatter.[2] That asymmetry is why toric, quadrant-specific, and impression-based landing zones exist, and why the findings below are often sectoral.
Lenses also settle into the conjunctiva over the first hours of wear, which a 2025 review attributes mainly to tissue compression under the landing zone. If too little clearance was built in, settling can produce limbal or corneal bearing.[3]
Findings, what they mean, and who acts
| Finding | Usual meaning | First response |
|---|---|---|
| Faint impression ring after removal, no blanching or staining | Expected compression, usually benign | Note it |
| Blanching during wear, rebound hyperemia after removal | Landing zone compression | Fitter |
| Edge digging into conjunctiva, staining at edge | Impingement | Fitter |
| Fluorescein pooling under the edge, bubbles entering | Edge lift | Fitter |
| Tissue drawn under the lens at the limbus | Conjunctival prolapse | Fitter |
| Limbal staining, limbal haze, or new vessels | Limbal bearing or hypoxia | Fitter, promptly |
| Inflamed pinguecula under the landing zone | Pingueculitis | You treat; tell fitter |
| Conjunctival cyst at the edge | Impingement microtrauma | Fitter; you if excision needed |
Compression and blanching
What you see: whitening of conjunctival vessels, circumferential or in a sector, at the inner or outer edge of the landing zone, sometimes with hyperemia just beyond the edge. After removal, an impression ring.[3]
How to read it: the 2025 review treats blanching during wear followed by rebound hyperemia in the same area after removal as pointing to mechanical compression. An impression ring alone, without blanching or staining, is generally considered benign and typically resolves within a few hours. Some patients have a hypersensitive conjunctiva that reddens with any manipulation, which complicates the picture.[3] Persistent redness and discomfort from compression can shorten wear time and lead to intolerance.[3]
What the fitter can change: flattening the peripheral curves, or moving to a toric or quadrant-specific landing zone to match scleral asymmetry.[3] A 2026 case series of poorly fitted lenses showed that design changes can let patients resume wear, and advised reassessing both fit and underlying disease at scheduled intervals.[12]
What imaging shows under the landing zone
Several small studies have measured changes that the slit lamp may not show. Their long-term clinical significance is unknown.
- OCT angiography, 13 wearers of spherical mini-scleral lenses: inferior conjunctival vessel density under the lens fell after 1 hour of wear compared with at least 8 hours lens-free, and clinician-graded impingement on slit photographs correlated with the OCT-A findings in three quadrants.[4]
- Functional slit lamp imaging, 19 eyes over 3 hours: conjunctival morphology under the landing zone changed progressively during wear, with associated changes in blood flow and vessel density.[5]
- Long-term wear, 17 keratoconus eyes: conjunctival-episcleral thickness was lower than in healthy controls, especially superiorly and inferiorly, and superior thinning correlated with years of wear; scleral thickness itself did not differ.[6]
- Single-subject pilot: with increasing sagittal height, OCT-A showed perilimbal vascular interruption of 0%, 25%, and 75%.[7]
Impingement, edge lift, and staining
Impingement is the lens edge pressing into conjunctiva; edge lift is the opposite, with fluorescein pooling under the edge and sometimes bubbles entering the reservoir. Compression and impingement can occur together, and a lens can lift in one meridian while aligning well in the opposite one.[2] The 2022 review recommends assessing alignment in all gaze positions and again after several hours of wear, once the lens has settled.[2]
Conjunctival staining in one quadrant is worth recording by location for the fitter. Removal technique matters too: a 2025 review notes that placing the plunger too close to the lens center is a common error that can cause blanching, impingement, hemorrhage, and corneal or conjunctival staining.[3]
Conjunctival inclusion cyst: a case report describes an epithelial inclusion cyst of the bulbar conjunctiva from chronic edge impingement, managed with a lens modification (a MicroVault) rather than surgery. The authors note diameter changes or notches are the more common correction.[8]
Suction: a case report described intracorneal hemorrhage within 4 hours of application and removal training on the first day of wear, in an eye with long-standing keratoconjunctivitis, and framed it as a mechanical complication related to suction between lens and ocular surface.[13]
Pinguecula and pingueculitis
A raised pinguecula under the landing zone is a common reason for a notch or focal vault. In a retrospective keratoconus series of 157 eyes, pingueculitis occurred in 1.3% of eyes.[11] Treat the inflammation as you would in any patient and tell the fitter, who can offload that area.
Corneal surface findings after removal
- Epithelial bogging: elevated, swollen, waterlogged-looking epithelium after removal, with positive corneal or negative limbal fluorescein staining. Its cause is unknown, and current evidence suggests no long-term harm. Midday removal, rinsing, and reapplication, or a design change, may reduce it.[3]
- Epithelial bullae: negative-staining areas, often near the limbus, attributed mainly to mechanical compression with a hypoxic contribution. The review advises stopping wear until they resolve, which can take at least a week, then refitting to avoid excess vault and compression.[3]
The limbus
Scleral lenses are meant to clear the limbus entirely. Limbal bearing appears in a 2016 review’s list of findings unique to scleral lens wear.[1] The stakes are highest in limbal stem cell deficiency. In a retrospective series of 27 eyes with confirmed LSCD fitted with scleral lenses, acuity improved in 25.9%, was stable in 48.1%, and fell in 25.9%; LSCD stage improved in 25.9%, was stable in 29.6%, and worsened in 44.4%. Anterior segment OCT and fluorescein angiography in 5 eyes showed limbal compression and delayed filling, and the authors suggest limbal hypoxia may drive worsening.[9]
Across the wider wearer population, a practitioner survey covering 72,605 wearers estimated that 0.20% discontinued wear over one year because of limbal stem cell deficiency.[10] For vessels crossing the limbus, see scleral lenses and corneal neovascularization. For tissue drawn under the lens, see conjunctival prolapse.
Common questions
Is a red ring after removal normal?
A faint impression ring without blanching or staining is generally considered benign and typically fades within a few hours, according to a 2025 review. Blanching during wear with rebound redness in the same place after removal points to compression, which the fitter should address. Some patients have a reactive conjunctiva that reddens with any manipulation, which can make this harder to read.
Who should manage a pinguecula under the landing zone?
Both of you. Treat pingueculitis as you normally would and tell the fitter, who can relieve that area with a notch, a focal vault, or a quadrant-specific landing zone. In a keratoconus series of 157 eyes, pingueculitis occurred in 1.3%.
Can poor removal technique cause these findings?
Yes. A 2025 review describes plunger placement too close to the lens center as a common error that can cause conjunctival blanching, impingement, hemorrhage, and corneal or conjunctival staining. A subconjunctival hemorrhage after removal is worth mentioning to the fitter so technique can be checked.
Are scleral lenses safe for eyes with limbal stem cell deficiency?
They are used for it, and in one series vision improved or stayed stable in most eyes. But LSCD stage worsened in 44.4% of 27 eyes, and imaging in the eyes studied showed limbal compression and delayed fluorescein filling. The authors recommend close monitoring of fit in these compromised eyes.