Understand
How does a scleral lens improve vision?
Larger than a corneal lens, a scleral lens is made from a rigid, oxygen-permeable material. It rests on the conjunctiva covering the sclera and forms a vault over the cornea.
Before insertion, the lens is filled with sterile, preservative-free saline solution. This fluid layer optically neutralises corneal irregularities. The regular front surface of the lens then becomes the eye’s new optical surface.
Literature reviews describe scleral lenses as an effective solution for the visual rehabilitation of irregular corneas, particularly when other forms of correction do not provide an adequate result.
Who is it for?
When may scleral lenses be recommended?
- keratoconus and other corneal ectasias;
- scarring following infection, inflammation or trauma;
- an irregular cornea following refractive surgery or a corneal graft;
- irregular astigmatism that spectacles do not correct adequately;
- selected severe ocular surface diseases, as part of coordinated medical care.
Diagnosis and monitoring of corneal disease are the responsibility of the ophthalmologist. The lens fitting addresses the need for correction and visual rehabilitation within this care pathway.
Bespoke
A fitting process that assesses the entire lens
- Map the eye.Refraction, available topography or tomography, and examination of the cornea, eyelids and ocular surface.
- Trial an initial geometry.Clearance over the cornea, distribution of bearing on the sclera and stability are assessed after the lens has settled.
- Optimise vision.An over-refraction refines lens power. More complex corrections may be incorporated where useful.
- Learn the techniques.The lens must be inserted while full and without an air bubble, then removed, cleaned and disinfected using the method taught.
- Assess in real-life conditions.Lens behaviour after several hours of wear guides the final adjustments.
Complex corneas may require several trials. The fitting package starts at €70; lens prices are quoted according to the selected geometry.
Use
Insertion, care and comfort
The lens is filled to the brim with the recommended solution immediately before insertion. An air bubble beneath the lens can interfere with vision, cause discomfort and affect the ocular surface: the lens must be removed and reinserted.
Vision that becomes hazy over the course of the day may be caused by deposits or particles in the reservoir. Depending on the cause, lens geometry, care or wearing arrangements may be adjusted.
Tap water must never be used to fill, rinse or store a lens. The filling solution is not necessarily the cleaning solution: each has a specific role.
Limitations
What a scleral lens cannot promise
It does not restore an anatomically normal cornea, stop progressive keratoconus on its own or guarantee perfect visual acuity. The outcome depends on corneal transparency, the retina, the optic nerve and the eye’s other structures.
Handling difficulties, redness in the landing zone, haze, dryness or corneal swelling may require a modification or temporary interruption of wear.
if the eye becomes red or painful, light becomes difficult to tolerate, discharge appears or vision suddenly decreases. Do not reinsert the lens until advised by the professional caring for you.
