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Keratoconus is a condition that changes how light enters the eye, leading to blurriness, halos, and poor visual acuity. Because keratoconus alters the shape of the eye, even minute shifts in that shape can affect the performance of carefully calibrated lenses. Recognizing keratoconus vision changes is important so that the lenses can be updated promptly and patients can avoid the issues associated with lenses that are no longer adequate.
Why Do Keratoconus Prescriptions Need to be Updated?
In keratoconus, the normally round cornea becomes progressively thinner and bulges outward, creating an irregular, cone-like shape. This irregular shape increases myopia and astigmatism. It leads to more frequent changes than static refractive errors and often presents clinically as worsening astigmatism or keratoconus. In the early stages of the condition, glasses or soft contact lenses may still improve the vision.
As the condition progresses and the cornea becomes more irregular, most patients need to transition to specialty lenses such as rigid gas-permeable (RGP) or scleral lenses to achieve a more stable vision correction. Because keratoconus can continue to progress over time, even with advanced contact lenses, patients may still need periodic updates to their lens design and prescription.
Persistent Blurred Vision
One of the most common signs that your prescription needs updating is blurry vision. Patients often notice that letters look blurry when reading and that street signs or text have a faint double outline or a shadowed outline; this is often described as ghosting vision in keratoconus.
In keratoconus, these signs are often due to increased corneal irregularities, worsening astigmatism, and other refractive changes. If ghosting and blur persist and don’t improve with blinking or re-centering your lenses, it’s a strong indicator that your prescription no longer matches your cornea’s shape.
Difficulties Driving at Night
Worsening glare, halos, or starbursts around lights are another common sign that a keratoconus prescription may no longer be providing adequate correction. Patients often report that nighttime driving becomes more stressful, with lights appearing streaky or blurry, even when their vision seems normal during the day.
Night-driving challenges can arise when the optical zone of a contact lens no longer aligns with the pupil, or when corneal irregularities are not being fully corrected by the current prescription. If night driving has recently deteriorated, it’s time to schedule an assessment.
Reduced Lens Comfort
For many people with keratoconus, specialty lenses such as RGP and scleral lenses are key to clear vision and daily comfort. A noticeable reduction in comfort can indicate that the lens no longer fits the cornea as well as it once did. If your lenses feel heavy or sharp and irritate your eyes, it may indicate that the lenses need to be adjusted.
As the cornea bulges and its shape changes, a lens that once fit well can begin to press on the cornea in some spots and sit too far away in others. It’s important to monitor changing comfort levels, as poorly fitting lenses can cause corneal irritation and may even damage the delicate corneal tissue over time.
Fluctuating Visual Acuity
If your vision is clear in the morning and hazy in the afternoon, or it varies from day to day, it’s another common sign of a prescription that has changed. Visual fluctuations can reflect changes in lens position on the eye, corneal thickness, corneal hydration, and tear film distribution. In some cases, this can also be related to the lens not fitting optimally, which may lead to midday fogging. If your vision is clear right after inserting your lenses but gradually becomes foggy as the day progresses, it may indicate that your lenses need to be adjusted or refit to better match the current shape and needs of your cornea.
Eye Strain and Headaches
When the eyes have to work harder to compensate for uncorrected astigmatism or an underperforming prescription, patients may experience eye strain, headaches, or fatigue when reading or using screens. Eye strain is particularly noticeable if tasks like computer work or studying require more effort. You may notice that you tire more easily or that headaches occur after short periods.
Because keratoconus affects the sharpness and quality of vision, even small corneal changes can translate into disproportionate visual effort. If you are struggling with increased eye strain along with any of the other signs in this blog, it’s a strong indicator that your current lenses are not providing optimal correction.
Schedule a Keratoconus Prescription Review
Keratoconus is a chronic, progressive condition, but with regular monitoring and proactive prescription updates, patients can protect their long-term eye health. If you notice any of the signs above, or a combination of them, schedule a consultation as soon as possible. Contact Weston Contact Lens Institute to speak with a keratoconus expert and schedule an appointment. Together, we can explore whether a keratoconus contact lens adjustment can help you achieve clear, comfortable vision throughout the day.
