Scleral Contact Lenses

How a scleral lens works

The lens is filled with preservative-free saline and placed on the eye, where its edge lands on the sclera and its center vaults the cornea by a fraction of a millimeter. The saline fills the gap. Light passes through the lens's smooth front surface and the fluid layer to the cornea, and any irregularity in the cornea is neutralized because the fluid has almost the same refractive index as corneal tissue. The result is the optical equivalent of a perfectly regular cornea, whatever the real one looks like. The sclera has few nerve endings, so the lens is barely felt.

Who scleral lenses are for

• Keratoconus and pellucid marginal degeneration, at every stage, and after cross-linking once the cornea has settled
• Corneas after LASIK, PRK or RK that standard lenses cannot fit, including post-LASIK ectasia
• Corneal transplants, whose grafts are often steep, tilted or irregular
• Corneal scarring from injury or infection
• Severe dry eye, Sjogren's syndrome, exposure and neurotrophic keratitis, where the fluid reservoir protects and heals the surface
• High astigmatism and high prescriptions in patients who want rigid-lens optics with soft-lens comfort

Fitting

Corneal tomography and, where appropriate, scleral imaging map the eye. A diagnostic lens is placed and its vault over the cornea is assessed, with imaging where appropriate; the landing on the sclera is checked for even pressure; and vision is measured over the lens. The custom lens is ordered and refined over one to three further visits. Advanced designs with asymmetric back surfaces, toric peripheries and front-surface aberration correction may be considered when standard designs fall short.

Living with scleral lenses

Insertion uses a small plunger and takes practice for the first week; removal is simpler. Lenses are worn for the waking day and removed at night. If the fluid clouds during a long day, the lens is removed, refilled and reinserted in a minute. Cleaning uses a rigid lens solution, and the lens itself lasts one to two years. Follow-up checks the cornea beneath the lens and the fit, and the lens is refitted when the eye changes.

Cost

For keratoconus, transplants, scarring and severe dry eye, scleral lenses are frequently covered under medically necessary contact lens benefits, which our team checks before fitting. Otherwise, our team explains the costs before you start.