Scleral Contact Lenses are unique.
Nearly every contact lens on the market, both soft and hard, have one thing in common – they all rest on the cornea.
What are Scleral Contact Lenses?
Along with hard lenses and hybrid lenses, Scleral Contact Lenses are Specialty Contact Lenses that are designed to restore vision in patients with corneal disease or after corneal surgeries.
There are many situations (due to disease or surgery) where the cornea is not stable, uniform, or healthy enough for a contact lens. Scleral Contact Lenses are perfectly suited for this situation.
The very large diameter of Scleral Contact Lenses are designed to clear the cornea and rest only on the white of the eye called the Sclera.
Hence the name, Scleral Contact Lenses.
How do Scleral Contact Lenses Work?
Scleral Contact Lenses are designed to avoid touching the cornea completely.
Instead, these lenses ‘vault’ over the compromised cornea and rest only on the white of the eye.
Below are cross sectional images of one of our patients with Scleral Lenses showing how they work.
In the center there is no touching between the lens and the cornea.
On the white of the eye you can see the lens resting entirely on the sclera and clearing the cornea.
While this fitting concept might just seem novel, in reality there are very important and unique benefits of Scleral Contact Lenses for both vision and comfort.
Vision with a Scleral Contact Lens
With advanced corneal disease (like Keratoconus above), the ocular surface is so distorted and irregular that clear vision is not possible. Certainly a cornea transplant (PKP) could be performed. However, the recovery from a corneal transplant is very difficult.
Because of their complete coverage of the cornea, Scleral Contact Lenses act like a PROSE (Prosthetic Replacement of the Ocular Surface Ecosystem). Basically a corneal transplant without a corneal transplant
By putting one of these lenses onto the eye, you are essentially replacing the diseased cornea with the smooth and uniform surface of the contact lens. Saline solution then fills up the area between the contact lens and the cornea to create a prosthetic visual system.
Comfort with a Scleral Contact Lens
While it might seem counter intuitive, Scleral Contact Lenses are even more comfortable than most SOFT contact lenses. How?
- The cornea has the most nerve endings of any tissue on the surface of the body. However, the sclera has very few nerve endings. By avoiding the cornea and only resting on the sclera, these lenses provide very little “awareness” feeling to the user.
- Because these lenses are so large, they are actually sit entirely behind the eyelids. Therefore, when you blink, you don’t rub across the edges of the contact lenses. This lack of lid interaction further enhances their comfort.
These two factors make Scleral Contact Lenses one of the most comfortable lenses to wear.
Who Needs a Scleral Contact Lens?
These large diameter hard lenses are not meant for the average contact lens wearer (below at left compared to a regular hard contact).
Scleral Contact Lenses are designed to work when glasses and conventional contact lenses fail.
By vaulting completely over the cornea, this contact lens option provides a new, smooth corneal surface that masks underlying problems with the cornea and allows clear vision and improved comfort when nothing else can.
There are quite a few indications for these lenses as outlined below.
Scleral Contact Lenses are particularly useful for:
- Ectatic corneal diseases where the contour of the cornea isn’t smooth but instead bulging and irregular: such as Keratoconus or Pellucid Marginal Degeneration.
- Irregular corneas after corneal surgeries (PKP, RK, LASIK, others)
- With corneal scarring after infection.
- Severe Dry Eye where the fluid reserve under the lens bathes the cornea throughout the day and improves comfort and quality of life.
If you have been told that you need specialty or medically necessary contact lenses in the past, but never had success due to vision or comfort problems.
We suggest that you ask your eye care provider, or schedule an evaluation at our office, to experience the comfort and clarity that Scleral Contact Lenses can provide.
Additional Links about Scleral Contact Lenses
- Inserting and Removing – Scleral Lens Education Society
- Boston Foundation for Sight
- GP Lens Institute
- Precision Family Eye Care: Scleral Lens Care and Handling Packet