Strabismus is a common visual condition where the eyes are misaligned, meaning they do not look at the same point simultaneously. This misalignment is often called “crossed eyes” or a “squint,” and it can involve one eye turning inward, outward, upward, or downward. Contact lenses can be worn with strabismus and offer several ways to manage the condition. They correct underlying vision problems and, in specialized forms, can directly address the misalignment or its symptoms.
Correcting Vision With Standard Contact Lenses
Standard contact lenses primarily correct refractive errors common alongside strabismus, such as nearsightedness, farsightedness, or astigmatism. Correcting these errors is an important first step because the eye’s effort to focus can influence the degree of misalignment. For example, in accommodative convergent strabismus, where the eyes turn inward due to focusing strain, providing a clear image with a corrective lens can help the eyes align better.
Standard soft contact lenses are the most commonly chosen type, offering comfort and ease of use. RGP lenses are another option, often providing sharper vision, especially for individuals with significant astigmatism or irregular corneal shapes. These standard lenses improve visual acuity and correct focus, which can indirectly help with alignment. However, they are not a direct treatment for the eye turn itself and do not actively force the misaligned eye into a straight position.
Targeting Misalignment With Specialized Lenses
Specialized contact lenses are available to directly manage the visual effects or appearance of strabismus. Prism contact lenses are one option, designed to help the brain fuse images from the misaligned eyes by bending the light entering one or both eyes. This light-bending power can eliminate or significantly reduce the double vision that often results from strabismus.
Prism lenses are generally suited for smaller deviations, typically up to ten prism diopters, and serve as a discreet alternative to thick prism glasses. The prism element shifts the image seen by the weaker eye, bringing it into better alignment with the dominant eye’s image. This improves binocular vision, allowing the eyes to work together more effectively and relieving associated symptoms like eye strain.
Cosmetic and Occlusion Lenses
Another specialized category includes cosmetic or prosthetic contact lenses, which mask the appearance of a noticeably misaligned eye. These lenses often have an opaque or tinted iris section to match the other eye, making the eye turn less apparent. Some lenses are also designed for occlusion therapy, where the center is purposefully blurred or opaque to block vision in the dominant eye. This technique is used as an alternative to an eye patch to encourage the brain to rely on and strengthen the vision in the weaker eye.
Making the Decision: Consultation and Ongoing Care
Deciding on and fitting contact lenses for strabismus requires the expertise of an eye care professional, such as an ophthalmologist or optometrist, who specializes in strabismus and binocular vision. A comprehensive examination determines the specific type and severity of the misalignment, which is crucial for selecting the most appropriate lens technology.
Factors influencing the decision include the patient’s age, their ability to handle and maintain the lenses, and the severity of their refractive error and misalignment. Once a lens type is selected, a precise fitting is performed to ensure the lens rests correctly on the eye, which is especially important for specialized lenses like prisms.
The patient must be thoroughly trained on the proper hygiene and care required for their lenses to prevent complications like infection. Regular follow-up appointments are necessary to monitor the effect of the lenses on both vision and eye alignment, allowing the practitioner to make any needed adjustments to the prescription or lens type.