Putting in new contact lenses and finding your vision blurry, especially with astigmatism, can be frustrating. This is a common phenomenon and usually does not indicate a problem with your eyes or the prescription. Astigmatism is a refractive error where the eye’s front surface, the cornea or the lens, has an imperfect curvature, shaped more like a football than a basketball. This irregular shape causes light to focus unevenly on the retina, resulting in distorted or blurry vision at any distance. This unique eye shape requires a specialized contact lens design to achieve clear vision.
Understanding Astigmatism and Toric Lenses
Correcting astigmatism requires a lens with different focusing powers across its surface, leading eye care professionals to prescribe toric contact lenses. Unlike standard spherical lenses, toric lenses incorporate two distinct powers oriented perpendicular to each other. This design counteracts the uneven curvature of the astigmatic eye. The cylinder power in a toric lens must be aligned precisely with the axis of the astigmatism to function correctly. The lens must remain stable on the eye to provide consistent vision.
Normal Adaptation and Expected Initial Blurriness
When inserting any new contact lens, a temporary period of blurriness is a normal part of the adjustment process, involving both physical and neurological adaptation. Physically, the lens needs time to settle onto the corneal surface and interact with the tear film until it finds its stable resting position. This settling process can take minutes to a few hours, during which slight shifting may cause vision to fluctuate. Neurologically, your brain must adapt to the newly corrected image, especially if the prescription changed significantly. If the blurriness is mild and gradually improves over the first few days, it is likely due to this expected adjustment period.
Why Toric Lenses Cause Unique Vision Issues
The most significant cause of persistent blurriness specific to astigmatism correction is the rotational instability of the toric lens. For a toric lens to work, the cylinder correction must be perfectly aligned with the astigmatic axis of your eye. Even a slight rotation of the lens, as little as a few degrees off the intended axis, can cause significant visual distortion, ghosting, or shadowing. Since contact lenses are not clamped onto the eye like glasses, they naturally move when you blink. Manufacturers incorporate specialized features to ensure the lens quickly returns to the correct orientation after a blink.
Stabilization Mechanisms
These stabilization features include methods like prism ballast, where a section of the lens is subtly weighted to leverage gravity and the natural pressure of the lower eyelid to keep it oriented downward. Another common method is dynamic stabilization, which involves thinning the lens material in specific zones to interact with the upper and lower eyelids during a blink, forcing the lens back into alignment. If the lens does not fit correctly, or if the stabilization mechanism fails to counteract the forces of blinking and eye movement, the lens will rotate out of position. This rotational misalignment is the primary mechanical failure causing a new toric lens to perform poorly.
Troubleshooting Other Potential Issues and Next Steps
If the blurriness persists beyond the first few days, or if vision is consistently fluctuating, the cause is likely a mechanical issue or a prescription mismatch. One common issue is tear film instability, often caused by dry eyes, which destabilizes the lens and leads to rotation and blurriness. Additionally, the overall fit of the lens, including its diameter or base curve, might be incorrect for your corneal shape, causing it to sit improperly or rotate excessively. A manufacturing error in the lens’s power or axis, or a subtle change in your underlying prescription, could also be the culprit.
If repeated blinking does not bring the vision back into focus, contact your eye care professional. The next step is a follow-up appointment where the practitioner will assess the lens fit using a specialized instrument called a slit lamp. During this examination, they observe the precise rotational position of the lens, often using tiny reference marks, to determine if it is misaligned or rotating too much. They can then adjust the prescription axis or try a different lens brand with an alternative stabilization design to achieve clear, stable vision.