Approximately 1 in 3 people have astigmatism, a vision condition that causes blurry and distorted vision.
If you have astigmatism, there is a wide variety of contact lens options that can provide you with clear and sharp vision.
What is astigmatism?
Astigmatism occurs when the curvature of the cornea, the front of the eye, is irregularly shaped. In normal circumstances, the cornea is a spherical shape, like a basketball or baseball.
Astigmatism is characterized by an irregularly shaped cornea, typically an oval shape, that resembles a football.
This oval shape prevents light from bending and focusing accurately onto the retina— resulting in blurred or distorted vision.
Astigmatism can be congenital or can develop later on in life from an eye injury, surgery, or an eye condition called keratoconus.
Symptoms of astigmatism include:
- Distorted vision
- Blurred vision
If you experience any of the signs above, contact an eye doctor near you, who can diagnose and treat the visual issue.
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Specialized contact lenses for astigmatism
Since the shape of the cornea is irregular, traditional ‘spherical’ soft contact lenses are generally not suitable for patients with astigmatism.
However, if you have mild astigmatism, then a soft toric contact lens can be worn. Higher levels of astigmatism generally require the use of rigid gas permeable (RGP) contact lenses or scleral contact lenses.
What are toric contact lenses?
Toric contact lenses are designed to correct astigmatism and provide clear vision.
These lenses are designed to match the corneal shape and contain varying powers throughout the lens in order to correct the different amounts of refractive errors that present in different areas of the cornea.
Toric lenses have a unique design that enables the contact lens to rotate on the cornea until it finds the correct position and orientation for proper alignment and clear vision.
However, since the range of corrective powers is limited with toric lenses, they are generally not recommended for moderate to high levels of astigmatism.
Rigid gas permeable (RGP) contact lenses
Rigid gas permeable (RGP) are also known as ‘hard’ contact lenses are also used for the correction of astigmatism.
Rigid gas permeable lenses retain their spherical shape on the eye, instead of adjusting to the shape of the irregular cornea.
The surface of the GP lens actually acts as a replacement for the irregular cornea, thereby correcting the astigmatism by enabling the contact lens to refract the light properly.
Gas permeable lenses are known for providing sharp, clear vision when fitted properly.
For high amounts of astigmatism, GP contact lenses with a toric design may be recommended— though in most cases, the toric design is not necessary.
Scleral contact lenses
Scleral lenses are a specialized GP contact lens that contain a large-diameter which allows them to vault over the cornea, instead of resting directly on its surface.
Scleral lenses are custom made, and are a great contact lens option for astigmatism correction, even in cases of significantly high astigmatism.
By arching over the cornea, scleral lenses create a space between the cornea and the contact lens. This dome-like space acts as a liquid reservoir which provides constant hydration to protect the cornea and increases comfort for all-day contact lens wear.
Thanks to their rigid surface and personalized fit, scleral lenses provide sharper visual acuity than standard soft contact lenses, with a high level of comfort.
Hybrid contact lenses
Hybrid contact lenses are a combination of soft lenses and RGP lenses.
These lenses have a central zone that consists of RGP material, and are surrounded by a fitting zone made of a soft or silicone hydrogel material.
Hybrid contact lenses are custom made and offer the best of both worlds when it comes to contact lenses for astigmatism— the sharp vision of GP lenses and the comfort of soft toric lenses.
Since hybrid contact lenses are significantly larger than GP lenses and also contain thinner edges, they are less likely to dislodge from the eyes— this is something to take into account if you play sports on a regular basis.
If you have astigmatism and are looking for contact lenses that give you clear, comfortable vision, speak to an optometrist who has experience fitting contact lenses for astigmatism.
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Schedule an appointment with an eye doctor to discuss how to achieve the best vision possible.
Your optometrist will discuss all of the contact lens options that are best suited for you and your individual needs.
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