Having an astigmatism doesn’t mean you have to give up wearing contact lenses!
“Normal” contact lenses (also known as spherical contact lenses) don’t adequately address the irregular curvature of the eye in astigmatism, meaning you may still experience blurry or distorted vision.
Soft toric contact lenses and scleral contact lenses are specially designed to correct corneal and lens irregularities to provide clear vision for those with mid to high astigmatism.
What is an Astigmatism
Astigmatism is a common refractive error caused by an irregularly shaped cornea or lens.
In an eye with no astigmatism, the shape of the cornea or lens is perfectly round. When light enters the lens and is refracted by the cornea, light is focused directly on the retina, allowing for clear vision.
When light enters an eye with astigmatism, the uneven curvature of the cornea or lens causes light rays to scatter and focus on multiple points, either in front of or behind the retina. This scattering of light results in blurred or distorted vision, as the retina receives an imperfect image.
People with astigmatism might experience difficulties with tasks that require sharp vision, such as reading, driving, or recognizing faces. The degree of blurriness depends on the degree of irregularity in the cornea or lens. Mild astigmatism may cause slight blurriness, while severe astigmatism can significantly affect visual clarity.
The exact cause of astigmatism is unknown, but we know that genetics, eye injuries, surgeries, and certain conditions can play a role.
Common symptoms of astigmatism include:
- Blurred or distorted vision at any distance
- Eye strain or discomfort
- Headaches, particularly after prolonged visual tasks
- Difficulty seeing at night
- Squinting to see clearly
- Double vision in one eye
- Halos around lights
Astigmatism often coexists with other refractive errors such as myopia, hyperopia, and presbyopia. It’s also possible to have astigmatism without any other refractive error.
Contact Lens Options for Astigmatism
Astigmatism is generally not considered a serious eye condition, but it can significantly impact vision quality and daily activities if left untreated. An uncorrected refractive error can cause chronic eye strain, headaches, and difficulty concentrating.
Contact lenses can effectively correct astigmatism. However, not all contact lenses are suitable. Traditional spherical lenses, designed for correcting myopia or hyperopia, may not adequately address the irregular curvature of the eye in astigmatism.
Unlike “regular” (sphere) contact lenses, toric contact lenses, and scleral contacts are specifically designed to address the irregular curvature of the cornea or lens associated with astigmatism.
For those with high astigmatism (a degree of astigmatism greater than -2.00 diopters) wearing contact lenses can be more challenging. High astigmatism requires precise correction, and specialized lenses are often needed to provide clear vision and comfort.
Soft Toric Contact Lenses
Soft toric contact lenses are specifically designed to correct astigmatism by addressing the unique curvature of the cornea or lens. Made from soft, flexible materials, these lenses conform to the shape of the eye, providing comfort and stability.
They are available in daily, bi-weekly, and monthly disposable options, catering to various preferences and lifestyles.
Unlike regular spherical contact lenses, which have uniform power throughout the lens, toric lenses have different optical powers and focal lengths. This design helps refocus light onto the retina providing clearer vision.
Scleral Contact Lenses
Scleral lenses are a type of rigid gas-permeable lens (RGP) that are larger than conventional hard contacts. Unlike smaller RGP lenses that rest directly on the cornea, scleral lenses extend onto the sclera.
Scleral lenses function by creating a tear-filled vault over the cornea. The space between the lens and cornea is filled with a saline solution, offering comfort and hydration. This vault provides a smooth refractive surface that corrects visual distortions and offers unparalleled comfort.
Scleral lenses correct astigmatism by creating a new, uniformly curved refractive surface. This smooth surface effectively neutralizes the irregularities of the cornea that cause astigmatism. This creates a consistent optical shape, providing sharp, clear vision.
The unique technology and shape of scleral contacts make it a suitable corrective option for high astigmatism, severe dry eyes, and other corneal irregularities.
Importance of Contact Lens Fittings
Contact lens fittings are important to finding the most suitable contact lens tailored to your vision prescription and lifestyle requirements. An accurate fitting for astigmatism correction confirms these lenses align correctly with your eye’s unique structure for adequate vision correction and comfort.
For soft toric lenses, a fitting is important because these lenses have different refractive powers in different meridians to correct the uneven curvature of the eye. If not properly fitted, toric lenses can rotate on the eye, leading to inconsistent vision correction and discomfort.
In the case of scleral lenses, the fitting process involves detailed measurements because these lenses cover the entire corneal surface. A correct fit confirms the lens vaults uniformly over the cornea, creating a consistent and smooth refractive surface for vision correction.
The fitting process typically includes multiple steps, an initial evaluation, trial lens fitting, and follow-up visits to fine-tune the fit.
During these visits, your optometrist will take exact measurements, assess how the lens sits on the eye, and make any necessary adjustments. A proper fitting not only enhances visual clarity but minimizes the change of lens discomfort, dryness, and eye strain.
Schedule a Contact Lens Fitting!
Having astigmatism does not mean glasses are the only option for vision correction. Toric soft contact lenses and scleral contact lenses are excellent options for many individuals with varying levels of astigmatism.Connect with our team at Northern Lights Eyecare to schedule a contact lens fitting!
