Contact lenses remain one of the most popular and effective solutions for refractive eyes. They sit on the surface of the eye, changing the way light is refracted through it so that it hits the retina correctly. This means that the message that is passed from the retina to the brain via the optic nerve is correct and ensures the patient has clear, sharp and uncompromised vision.
Nevertheless, despite being very effective, generic contact lenses are not necessarily a suitable solution for everyone. There are several types of patients, including those with corneal abnormalities and those suffering from dry eye disease, who will find that they are unable to use conventional contacts. Fortunately, experts have developed a range of specialty contact lenses to enable those patients to still be able to experience all of the benefits of this solution. These are known as scleral lenses.
Scleral lenses are a form of specialty contact lens that are designed specifically for patients for whom regular lenses are unsuitable. They take their name from the fact that the contact between the lens and eye is made purely on the sclera, which is the white part of the eye. This is in contrast to regular contact lenses which make consistent contact across the entire eye. The remainder of the scleral lens vaults over the top of the eye, leaving a space beneath it.
Scleral lenses are made from a rigid, but gas-permeable material. This means that the lenses have the strength and stability needed to be retained across the cornea but allow enough oxygen to penetrate the eyes so that they do not dry out and are healthy and comfortable to move around.
The design of scleral lenses is important for several reasons. Firstly, the space between the lens and eye acts as a reservoir for tear film, keeping the eyes moist and comfortable and helping to alleviate the symptoms of dry eye disease. Secondly, the space allows for corneal irregularities, such as the bulge that is associated with keratoconus. This means that scleral lenses can be worn comfortably, and patient vision becomes clear. Their size also makes them far less likely to be dislodged from the eye, giving patients additional stability when it comes to their contact lenses.
You could be forgiven for thinking that all scleral lenses are the same, but in fact, there are three different varieties. What sets them apart is their size as this determines on which part of the sclera the lens makes contact. Conventional contact lenses are normally between 8-10mm in diameter. However, scleral lenses can vary between 14-20mm depending on the type that you have.
Full scleral contact lenses are the largest type and have the greatest space between the surface of the eye and the back of the lens.
Mini scleral contact lenses are the mid-sized variety and make contact with the anterior part of the sclera.
Semi-scleral lenses are the smallest variety and make contact at the junction between the cornea and sclera. However, they are still much larger than conventional contact lenses.
If you find that conventional contact lenses aren’t suitable for you, you might benefit from scleral lenses instead. To find out more about this solution, or to schedule a consultation to discuss your candidacy for scleral lenses, please get in touch with our Omaha office today by calling (402) 383-0780.