Unless you have extensive experience wearing contact lenses, you may believe that all contacts are identical. After all, they share a similar form and style. In reality, however, numerous types of contact lenses are available, so there is a wide range of options to accommodate virtually every patient. This is especially crucial, considering that some patients require speciality contact lenses.
Speciality contacts are lenses designed for patients with corneal conditions or other eye issues that are incompatible with conventional contacts.
Since conventional contact lenses rest directly on the surface of the eye and cover the cornea, they must suit properly and comfortably. However, since not everyone has a precisely shaped cornea, not everyone can wear conventional contact lenses. Some individuals also have eye conditions, such as dry eye, that make donning conventional contact lenses challenging.
Fortunately, there are a variety of speciality contact lenses that can mitigate these issues and allow these patients to see clearly without spectacles.
Rigid gas-permeable contact lenses
Gas-permeable contact lenses are sometimes prescribed to patients with dry eyes. Since the material allows sufficient oxygen to travel through to the cornea, the eyes do not dry out as quickly, resulting in greater comfort. And even though they are not hard lenses, their rigidity helps the cornea maintain its shape while donning them, which can aid in treating certain corneal disorders.
Scleral contact lenses
Scleral contact lenses have a larger diameter than conventional contacts. Still, instead of resting directly on the cornea, they cantilever over it, leaving a space between the cornea and the lens. Scleral lenses are a practical solution for various issues that could make donning conventional contact lenses impossible or impractical. The space allows patients with corneal abnormalities such as keratoconus or surgical scarring to wear contact lenses. Additionally, it functions as a reservoir for tear film, maintaining it on the surface of the eyes for a longer period of time and alleviating dry eye symptoms.
Limbal fit contact lenses
Limbal contact lenses are another speciality lens whose diameter lies between rigid gas-permeable and scleral lenses. Their larger diameter increases their stability on the corneal surface of the eye. They also provide minimal interference with the eyelids, contributing to your comfort and vision acuity.
Orthokeratology contact lenses
Orthokeratology is a novel method for correcting vision and preventing the progression of refractive error myopia. Orthokeratology lenses are manufactured from a material that makes them safe to wear overnight and is customised for each patient. While you sleep, the shape of the lenses and the natural tear film in your eyes gradually reshape your cornea, allowing you to wake up without the need for daytime contact lenses.
In addition to allowing patients to see clearly without daytime contact lenses, orthokeratology lenses have proven to reduce myopia progression in children. This is significant because it may also prevent complications associated with severe myopia, such as glaucoma, macular degeneration, and retinal detachment.