Yes, contact lenses can correct astigmatism. Advancements in lens technology make it possible to offer clear, stable vision for many individuals. These specialized lenses address the unique visual needs associated with this common eye condition.
Understanding Astigmatism
Astigmatism is a common eye condition causing blurred or distorted vision at all distances. It occurs when the cornea or lens inside the eye has an irregular curvature. Instead of being perfectly spherical like a basketball, the affected part of the eye is shaped more like an American football or an egg.
This irregular shape prevents light rays from bending uniformly, causing light to focus on multiple points rather than a single sharp focal point on the retina. This can lead to symptoms such as eyestrain, headaches, and difficulty with night vision. Astigmatism is often present from birth and can occur alongside nearsightedness or farsightedness.
Contact Lenses Designed for Astigmatism
Contact lenses designed to correct astigmatism feature specialized designs. The most common type is a toric lens. Unlike standard contact lenses, which have a uniform spherical curve, toric lenses are shaped like a slice from the side of a donut. This unique shape allows them to have different refractive powers across their surface, aligning with the varying curvatures of the astigmatic eye.
Toric lenses are engineered with specific features to ensure stability and prevent rotation, which is important for maintaining clear vision. Manufacturers integrate design elements such as prism ballast, thin zones, or truncation. These features help the lens settle into the correct orientation and resist movement with blinks, providing consistent visual clarity. Toric lenses are available in daily, weekly, and monthly disposable options.
Another option for correcting astigmatism is rigid gas permeable (RGP) lenses. Made from a firm, oxygen-permeable polymer, RGP lenses are more rigid than soft toric lenses. They maintain their shape on the eye, creating a new, smooth refractive surface over the cornea. This rigidity can be particularly beneficial for individuals with higher levels of astigmatism or irregularly shaped corneas, often providing sharper vision.
Hybrid contact lenses combine characteristics of both RGP and soft lenses. They feature a rigid gas permeable center for clear vision surrounded by a soft outer skirt. This design aims to offer the visual acuity of RGP lenses with the comfort of soft lenses. These specialized lenses are often considered for those who may not achieve optimal results with toric lenses or find RGP lenses less comfortable.
The Contact Lens Fitting Process
Obtaining contact lenses for astigmatism involves a comprehensive eye examination and precise fitting. The eye care professional conducts various measurements to assess the eye’s unique shape. Key measurements include corneal curvature, often determined using a keratometer or corneal topographer, and identifying the specific axis and cylinder power of your astigmatism. The cylinder value indicates the degree of astigmatism, while the axis specifies its orientation on the eye, typically measured in degrees from 0 to 180.
Following initial measurements, trial lenses are selected based on the prescription and placed on the eye. The eye care professional evaluates how the lens fits and moves, ensuring it aligns properly to correct the astigmatism. This step is important because toric lenses must remain stable in a specific rotational position for optimal vision. Multiple trial lenses might be necessary to achieve the best fit, as slight variations can impact comfort and visual clarity.
Follow-up appointments are scheduled to monitor lens fit and assess vision over time. During these visits, the eye care professional confirms the lenses continue to provide clear vision and remain comfortable. This iterative process ensures the chosen contact lenses are well-suited to the individual’s eyes and lifestyle.
Wearing and Caring for Astigmatism Lenses
Wearing contact lenses for astigmatism involves specific considerations for comfort and effectiveness. Toric lenses have a particular orientation on the eye, important for proper vision correction. While manufacturers incorporate features to stabilize the lens, some individuals may experience a brief period where the lens shifts slightly before settling into its correct position, especially during the initial adjustment. This adjustment time can vary, typically from a few days to a couple of weeks, as the eyes and brain adapt to the new visual input.
Proper hygiene and care routines are important for maintaining eye health and lens longevity. Before handling lenses, wash hands thoroughly with soap and water and dry with a lint-free towel. For reusable lenses, a fresh, multipurpose disinfecting solution recommended by the eye care professional should be used for cleaning and storage. This typically involves placing the lens in the palm, applying solution, gently rubbing, rinsing, and then placing it in a clean case filled with fresh solution for disinfection.
Lens cases should be rinsed with fresh solution and air-dried after each use, and replaced regularly, approximately every three months, to prevent bacterial buildup. Adhere to the prescribed replacement schedule for the lenses (daily, weekly, or monthly) and avoid wearing them beyond their recommended duration. If discomfort, persistent blurriness, redness, or dryness occurs, consulting an eye care professional is recommended, as adjustments to the lens type or care routine may be necessary.