by Elise Kramer, OD
Scleral contact lenses rest their weight on the sclera and vault over the cornea. These lenses are effective for resolving vision-related issues secondary to irregular corneas, refractive errors and many other conditions.
However, while scleral lenses are often the norm in advanced contact lens practices, they tend to be unfamiliar territory for primary care optometrists.
To help you understand these lenses, why they work and how they are typically used, we compiled this list of five little-known scleral lens facts.
Scleral lenses pre-date other contact lenses. Although soft contact lenses are typically considered the standard, scleral lenses have a longer history.
The first successful scleral lens (or perhaps, more correctly, scleral shell) was designed in 1887 by two German brothers, Friedrich A. and Albert C. Müller. They sat on the sclera, vaulted over the cornea and left a chamber between the lens and the eye that was filled with saline solution. These lenses were not perfect; they were made of blown glass and were large, heavy and not permeable to oxygen. These flaws would later be corrected to yield the modern scleral lenses we use today.
Scleral lenses are comfortable despite their size. First-time scleral lens users often worry that the lenses won’t be comfortable, mostly because of their size and rigidity. While scleral lenses are considerably bigger than standard soft lenses, they are just as comfortable — if not more so.
Scleral lenses are designed specifically based on the shape of the individual eye they are being fitted to. They are designed to land gently on the sclera, without causing any compression or stress to the underlying tissue.
Scleral lenses work even when other lenses don’t. Scleral lenses are useful when a patient can’t seem to find a contact lens that works well or solves their vision issue.
Each scleral contact lens is custom-made for the patient. The lenses need to be fitted to vault over the cornea to maintain a constant reservoir of fluid between the lens and cornea. This design ensures the eye remains hydrated during the entire time the lens is worn. In addition, the fluid layer helps compensate for any irregularities in the shape of the cornea, which improves vision.
Scleral lenses are not exorbitantly expensive. One of the most commonly recited myths about scleral lenses is that they are much more expensive than standard soft lenses. Because the lenses must be fitted and customized to fit each individual eye, there is more work involved in prescribing scleral lenses, which many patients assume will lead to higher cost. Patients are often surprised to discover scleral lenses are not excessively expensive.
These lenses are often covered by insurance and, even when they aren’t, they provide enough of an improvement over regular lenses — in both comfort and vision — that patients are happy to make the investment. What’s more, if the lenses are adequately cleaned and maintained, their lifespan can exceed that of any other type of lens.
Scleral lenses can promote healing of the ocular surface. Correcting vision is only part of what scleral lenses do. They also protect the eye by exposing it to an oxygen permeable fluid-filled chamber. This setup gives the eye the moisture and oxygen it needs to stay healthy, but also protects it from outside threats or irritants. As a result, scleral lenses are fantastic for promoting healing of the ocular surface, whether after a corneal transplant or during the recovery period from a chemical or burn injury, for example.
The benefits associated with scleral contact lenses make them a popular and satisfying choice for many patients looking for clear and comfortable vision. Don’t overlook the advantages of scleral lenses; they are the highest level of technology available for patients today.
For more information:
Elise Kramer, OD, who is residency-trained, practices at Miami Contact Lens Institute and specializes in ocular health and disease, ocular surface disease, and regular and specialty contact lens fitting. Over the last few years she has created a unique scleral lens practice.
Disclosure: Kramer reports she is a consultant for Spectrum International Group.