If you are looking to wear contact lenses but have always had problems with comfort or have been told you'll never be able to wear contact lenses because of an irregularly shaped cornea or other eye problem, it may be time to look into a type of contact lens known as a “scleral lens.”
Large diameter, rigid gas permeable lenses, known as scleral lenses, are designed to comfortable pass over the entire cornea and fit perfectly on the sclera, the white part of the eye. Scleral lenses are a replacement for the irregular surface of the cornea with a perfectly formed optical surface, to ensure a perfectly clear vision that wouldn't be possible from eyeglasses or any other type of vision solution. This extra area also allows the lens to be a liquid reservoir to provide extra comfort for those who otherwise may have comfort issues with regular contact lenses.
These scleral lenses vary between 14.5 mm to 24 mm due to the various complexities or eye conditions, such as keratoconus or astigmatism. While mild versions of these eye conditions tend to use smaller, cheaper types of sclera lenses, the advanced cases of keratoconus, severe and chronic dry eyes or advanced ocular diseases often are considered more complicated to treat, and usually require larger, more costly, scleral lenses.
Scleral lenses are always custom made to fit the unique contours of your eye, so fitting of this type of specialty lens requires a specific expertise and a greater amount of time fitting than with standard gas permeable and soft contact lenses. In many cases, a digital map of your cornea will by created, displaying for your optometrist an image referred to as your “corneal topography.” This will help your eye doctor more easily find the right fit for you, and reduce the number of trial pairs and the amount of time spent in fitting.
Because of the increased amount of time that is required to obtain a corneal topography and customize a scleral lens that works best and is most comfortable for your eyes, as well as the larger material cost to produce, scleral lenses can be significantly more expensive than traditional gas permeable and soft contact lenses. Despite this, scleral lenses still remain the most comfortable and, in many cases, only way, to obtain comfortable, accurate vision for those suffering from severe dry eye, keratoconus and other similar eye conditions.
For more information, contact your eye doctor today.