Large-diameter gas permeable (GP) lenses, like conventional GP lenses, have many strengths when compared to soft lenses. These include:
- Sharper vision
- Greater durability
- Easier handling
- Reduced risk of complications
Normal GP lenses sit on the clear part on the front of the eye, also known as the cornea. Large Diameter Rigid Gas Permeable Lenses, also known as scleral lenses, vault over the entire corneal surface and rest on the “white” of the eye (the sclera).
Because of their size, scleral lenses are more stable on the eye and less likely to accidentally dislodge. This stability also offers additional comfort similar to soft lenses, especially for sensitive eyes or irregularly shaped corneas.
Types of Scleral Lenses
There are three categories of scleral lenses:
- Corneo-scleral lenses and semi-scleral lenses are much larger than conventional GP lenses and rest near the junction between the cornea and the sclera
- Mini-scleral lenses vault over the entire corneal surface and rest on the sclera
- Full scleral lenses are the largest scleral lenses and provide the greatest amount of clearance between the back surface of the lens and the cornea.
All modern scleral lenses are made with highly breathable, rigid gas permeable lens materials.
Even though they cover the entire cornea, plenty of oxygen reaches the surface of the eye to keep it healthy and comfortable.
Are you a good candidate?
Anyone interested in achieving the best vision possible with contact lenses should consider scleral lenses. However, they’re particularly helpful for the following conditions:
- Irregular corneas. Vision problems caused by an irregularly shaped cornea — whether naturally occurring, due to an eye condition such as keratoconus, or resulting from eye surgery — typically cannot be fully corrected with glasses or soft contact lenses. Scleral lenses typically will provide sharper vision for these eyes.
- Hard-to-fit eyes. If your eyes cannot be comfortably fitted with conventional GP lenses or the shape of your eye causes the lenses to dislodge too easily from your eyes (during sports, for example), scleral lenses can provide a more comfortable and secure fit.
- Dry eyes. If your eyes are too dry for conventional contact lenses, scleral lenses can help. In particular, the generous space between the back surface of full scleral lenses and the cornea acts as a tear reservoir to keep the front of your eye moist and comfortable.
Cost of Scleral Lenses
Scleral lenses are custom-made to the exact specifications prescribed by your optometrist to provide the best possible vision, eye health and comfort. Special automated measuring tools and imaging devices are often used to fit them. This makes them more expensive than other types of contact lenses. We can advise you of specific costs for your individual needs.