When selecting progressive lenses for your customer, you have the choice between fixed and variable corridor designs. Each design has its own advantages and disadvantages, and the key to maximizing the benefits of each is to prioritize good customer service by listening to your client.
Understanding how to best assist your customer, whether it be with progressive lenses or in general, relies on your ability to listen and engage in informative conversations with them. By allowing them to express any concerns about their current glasses and inquiring about their lifestyle, such as their level of activity, computer usage, near tasks, and vision priorities, you can use this information to determine which corridor design would best meet their needs. As an eye care professional, your knowledge and expertise can help you tailor the lenses to suit your client’s lifestyle effectively.
A common misconception is that variable designs offer only one option and are a one-size-fits-all solution. While this may appear to be the case when ordering lenses, especially through a vision insurance portal, it is not entirely accurate. In my view, a variable corridor still offers a level of flexibility, albeit with a more automated approach. Once the order is sent to the ophthalmic lab, an algorithm considers the prescription, frame details, and seg height to determine the appropriate corridor. Variable corridors can be advantageous for early presbyopes or individuals who prioritize intermediate and distance vision. They are also useful for customers with significant differences between their right and left prescriptions, or those who choose aviator-style frames where a fixed design may cut off the reading add power.
Fixed designs offer you, as the Eye Care Professional (ECP), greater control over the customization of the lens design. With a fixed design, you can adjust the segment height in the lens and shorten the corridor length. This allows the customer to quickly access the reading area and enjoy a wider field of view while reading, ensuring they fully benefit from their prescribed add power. This customization can be particularly beneficial when fitting a mature bifocal wearer with an add power greater than 2.25 in their first progressive lens, or when a customer switches from a frame with a smaller B measurement to one with a deeper B. Additionally, a myopic presbyope customer may prefer a shorter design based on my experience. It’s important to consider that a myope of -6.00 (or higher) has likely been experiencing peripheral blur when straying from their optical center for a long time, so sacrificing some peripheral vision may not significantly impact them.
Key terms to keep in mind as they are crucial in the process of selecting progressive lenses and specific corridors:
Corridor Length: The distance between the Fitting Point, which marks the start of the power gradient, and the target add value is typically defined as 85 percent of the add power.
Target Add Value: Depending on the design, the target add value may be classified as 85, 95, or 100 percent of the prescribed add value. Manufacturers have the flexibility to determine corridor lengths based on these target add values. When comparing corridor lengths between different designs, it is crucial to contact the manufacturer to clarify which target add value they use. As a rule of thumb, you should add approximately 2 mm to the corridor length of an 85 percent target add value design when comparing it with a 100 percent target value design.
Minimum Fitting Height: The distance from the Fitting Point to the center of the reading area varies depending on the manufacturer or design. Targeting the Minimum Fitting Height may result in truncating up to half of the available reading area. A common suggestion is to select a frame that permits adding between 2 mm and 4 mm to the Minimum Fitting Height. This adjustment helps ensure that the wearer experiences optimal comfort and functionality when reading.
As we delve into the realm of the corridor, eye care professionals now have the opportunity to tap into one of the most influential tools for fitting progressive lenses. By mastering the concept of corridors, you can avoid having dissatisfied customers in your office. Harness the ability to select the optimal corridor length to align patient needs and lens design with their frame choice. By introducing patients to the wonders of a seamless progressive lens experience, you’ll not only enhance their satisfaction but also boost your practice’s success.
