What is Astigmatism?
Astigmatism is a common refractive error that occurs when the cornea or the lens inside the eye has an irregular curvature. Instead of being evenly rounded, the surface of the eye is shaped more like an oval. This uneven curvature prevents light from focusing properly on the retina. As a result, vision can appear blurred or distorted at both distance and near. Astigmatism often occurs alongside nearsightedness or farsightedness, but it can also exist on its own.
Symptoms of astigmatism may include blurred vision, eye strain, headaches, and difficulty seeing clearly at night. Many people are born with some degree of astigmatism, although it can also develop or change over time. A comprehensive eye examination is necessary to diagnose astigmatism and determine its severity.
How Can Contacts Correct Astigmatism
Contact lenses can effectively correct astigmatism by compensating for the irregular shape of the cornea or lens. Unlike standard spherical contact lenses, which provide uniform correction across the entire lens surface, lenses designed for astigmatism have different optical powers in different areas. This design allows light to focus more accurately on the retina.
Toric contact lenses are the most commonly prescribed option for astigmatism. These lenses have specific orientation features that keep them properly aligned on the eye. Proper alignment is essential because even small rotations can reduce visual clarity. Modern toric lenses use advanced stabilization methods to maintain consistent positioning during blinking and eye movements.
Effectiveness of Contacts for Astigmatism
Contact lenses are highly effective for correcting most forms of regular astigmatism. Many patients achieve clear and stable vision that is comparable to or better than what they experience with glasses. Because contact lenses move with the eye, they can provide a wider field of view and reduce certain visual distortions that may occur with spectacles.
However, contact lenses may not be ideal for every individual with astigmatism. Irregular astigmatism caused by corneal scarring, keratoconus, or prior eye surgery may require specialized lens designs or alternative treatments. In some cases, glasses or a combination of vision correction methods may be recommended.
Fitting Contacts for Astigmatism
Successful correction of astigmatism with contact lenses depends on precise fitting. An eye care professional will measure the curvature of the cornea, the degree and orientation of astigmatism, and the overall health of the ocular surface. Trial lenses are often used to evaluate vision, comfort, and lens stability before a final prescription is issued.
Follow up visits are essential to ensure that the lenses are performing as intended. Even well designed lenses may require adjustments to optimize vision and comfort. Proper fit also helps reduce the risk of complications such as dryness, irritation, or inflammation.
Eye Health With Contacts
Maintaining good contact lens hygiene is important for long term eye health. Patients must follow recommended cleaning and replacement schedules and avoid wearing lenses longer than prescribed. Poor hygiene can increase the risk of infection and inflammation, regardless of the type of lens used.
Some individuals with astigmatism may also have dry eye disease, which can affect contact lens comfort. In these cases, specific lens materials, rewetting drops, or alternative correction options may be recommended. Addressing underlying ocular surface issues improves the likelihood of successful contact lens wear.
Candidates for Astigmatism Contact Lenses
Most people with astigmatism can wear contact lenses safely and effectively. Candidates should have healthy eyes, realistic expectations, and the ability to follow care instructions. An eye examination is the best way to determine whether contact lenses are appropriate and which type will provide the best visual outcome.