Receiving a new eye prescription should lead to clearer vision, but sometimes the experience is confusing, causing you to question the accuracy of your new lenses. An eye prescription is a precise set of measurements designed to refract light onto the retina, correcting common errors like nearsightedness, farsightedness, and astigmatism. If your new glasses or contacts feel wrong, the discomfort can stem from two main possibilities: a normal period of adjustment or a genuine error in the lens power or manufacturing.
Is the Prescription Wrong or Is It Adjustment
The human visual system requires time to adapt to any change in the way light is focused. When you receive a new prescription, your brain must recalibrate its interpretation of the visual world through the altered focal point. This adaptation process causes the initial discomfort many people experience with new eyewear. Common temporary symptoms include mild dizziness, a slight feeling of being off-balance, or minor peripheral distortion, sometimes described as a “fishbowl effect.”
These issues occur because the new lenses change how light rays bend, shifting the perceived location of objects in space. For example, if your astigmatism correction (cylinder and axis) has changed significantly, the brain needs to learn to process the altered curvature of the lens. Similarly, those transitioning to progressive lenses often experience temporary blurriness or a swaying sensation as they learn to use the multiple focal zones.
The typical adjustment period for a standard prescription change is usually a few days, but it can extend up to two weeks. If the prescription change was substantial, or if you are new to complex lenses like progressives, adaptation may take closer to three or four weeks. During this phase, symptoms should steadily improve; gradual improvement suggests the brain is successfully adapting. Wear the new glasses consistently during this time to encourage the brain to complete the adaptation process.
Identifying Definitive Signs of an Error
If discomfort persists beyond the standard adjustment window of two to three weeks, or if symptoms are severe and non-improving, the issue likely lies with an error in the prescription or lens manufacturing. A definitive sign is a constant, severe headache that remains after the initial days, suggesting persistent eye strain. Extreme, non-resolving blurriness that makes it difficult to see clearly at any distance is also a strong indicator of a flawed power measurement.
Another telling symptom is persistent double vision (diplopia) or a continuous sense of vertigo that makes walking or driving hazardous. An issue may be apparent if your visual acuity is worse with the new glasses than it was with your old pair. In a correctly manufactured lens, the optical center must align precisely with your pupillary distance (PD); an incorrect PD measurement can cause a prismatic effect, leading to discomfort and an inability to fuse the image.
Errors can occur during the eye examination itself, such as when the patient’s eyes are tired or dry, leading to inaccurate measurements. Alternatively, the error might happen during the fabrication process, such as a transposition error where the cylinder power or axis is incorrectly entered or manufactured. An incorrect axis misalignment, even by a few degrees in a high astigmatism correction, can severely distort vision.
Your Action Plan for Resolution
If you have worn your new prescription consistently for the recommended adjustment period and severe symptoms have not lessened, the first step is to stop wearing the new glasses. Temporarily reverting to your previous, more comfortable eyewear or going without correction, if safe, can relieve the strain while you seek a resolution. It is important to contact the prescribing provider, whether an optometrist or ophthalmologist, as soon as you suspect a problem.
When you call, clearly and professionally describe the specific, persistent symptoms and their duration, emphasizing that they did not improve after the adjustment phase. The provider will typically schedule a free re-examination, often called a “recheck,” to verify the original prescription measurements. This recheck helps determine if the initial refractive findings were accurate or if a new prescription is needed.
The optical dispenser, or the office where you purchased the glasses, should also verify the physical lenses against the written prescription. They use specialized instruments to confirm that the lens power, cylinder, axis, and pupillary distance match the doctor’s original order. If the lenses were manufactured incorrectly, the lab will typically remake them at no charge, as this falls under a manufacturing defect.
Most reputable eye care providers and optical labs offer a limited warranty period, often 30 to 90 days, during which they will adjust the prescription or remake the lenses without a fee if an error is confirmed. If the recheck confirms a change in the prescription is necessary, the doctor will write an amended prescription, and the optical dispenser will proceed with a remake. Clear and objective communication of your symptoms will streamline this process and ensure a prompt resolution.