When multifocal lenses arrive from the lab, they may appear ready to use, but for optometrists, the work doesn’t end there. To ensure that every customer receives precisely calibrated, high-quality lenses, we conduct a rigorous series of checks. Even the smallest deviation can affect visual comfort and adaptation. So, how do we make sure that the lenses were manufactured exactly as ordered? This is a meticulous, controlled process that consists of several critical steps.
Step 1: Prescription Verification
The first step in quality control is matching the lenses to the original prescription. Using advanced optical instruments like a lensmeter, we measure the diopter strength in each focal area—distance, intermediate, and near vision. If even a minor discrepancy is found, we determine whether it’s a manufacturing error or a result of optimized lens technology adjustments that were intentionally made to enhance the viewing experience.
Step 2: Checking Optical Center Alignment
One of the most common issues with multifocal lenses is a misalignment of the optical center—the exact spot where light converges to provide clear vision. If the optical centers don’t match the customer’s pupillary distance (PD), as measured during the initial eye exam, the result can be blurry or uncomfortable vision. We use digital measuring devices to ensure that the centers are positioned with absolute precision.
Step 3: Assessing Lens Surface Quality
Each multifocal lens must be completely smooth and free from defects that could compromise its clarity. We inspect the lens surface under specialized lighting conditions that allow us to detect scratches, air bubbles, or microscopic distortions. Additionally, we conduct glare tests to verify the effectiveness of the anti-reflective coating, ensuring it is applied evenly and without any faded areas.
Step 4: Evaluating Lens Coatings
Lens coatings play a crucial role in enhancing durability and visual clarity. We check whether the lenses have received the correct coatings, including:
- Scratch-resistant coating – to protect against everyday wear and tear.
- Hydrophobic coating – to repel water, dust, and smudges.
- Anti-reflective coating – to reduce glare and improve contrast.
- Blue-light blocking coating – essential for customers who spend long hours on digital screens.
To confirm coating quality, we perform practical tests, such as water droplet tests to check if droplets slide off smoothly, and light reflection tests to ensure the anti-glare properties function correctly.
Step 5: Frame Alignment and Comfort Check
Once the multifocal lenses pass all quality control tests and are inserted into the selected frame, we conduct a final on-customer fitting. We verify that the lenses are positioned correctly, ensuring no additional height or angle adjustments are needed. Customers are asked to look in various directions to confirm smooth transitions between focal zones, avoiding any sensation of visual imbalance or instability.
A Commitment to Precision and Excellence
The extensive quality control procedures we follow guarantee that every customer receives perfectly calibrated multifocal glasses with optimal vision correction. We firmly believe that lens precision is non-negotiable, which is why we never compromise on quality.
In the next section, we’ll focus on the most important phase – adapting to multifocal glasses correctly to ensure a smooth, effortless transition from the very first day.