Driving Lenses: What makes them different and how to explain them to patients

By: Laurie Pierce

Vision is complicated enough. Daytime vision with progressive lenses that maximize distance, intermediate, or near vision also requires added thought and explanations. Even a balanced progressive or a task-specific progressive can take extra time to explain to our patients.

Even with these customized technologies in our toolbox, sometimes our patients struggle with night vision while wearing their daytime/everyday progressive lenses. This visual complaint requires a very specific optical solution: driving lenses.

While progressive lenses for everyday use, even for specific tasks, work fine, patients may still have a hard time seeing clearly while driving at night. IOT’s Endless Drive Progressive lenses are uniquely designed to help our patients who suffer from night myopia.

Night myopia is not a glare issue. When our patients present with a chief complaint of problems with glare at night, especially with streetlights and headlights, we immediately go to anti-reflective (AR) coatings, as we should. All lenses, in my opinion, should have AR coatings on both the front and the back surface to eliminate uncomfortable glare due to the reflectance factor. 

Some suggest that plano lenses with AR coatings can help with annoying glare at night. This is a myth. The reason for AR coating with Rx lenses is to eliminate the reflections caused by the lens surfaces. If there is no corrective lens needed, there is no need for a plano lens with AR coating…it is a corneal issue, perhaps dry eye, or other common corneal anomalies. If you have had patients exclaim that plano AR lenses solve their glare problems at night, it is a placebo effect.

Night myopia is different from nighttime glare problems. Night myopia is unique.

The simplest explanation of night myopia is that uncorrected myopia (or deliberate under-correction of myopia produced by maximum-plus refractions, Borish, 1970) is less noticeable during the day. At night, especially while driving, there is less light entering the eye which dilates the pupil, uncovering manifest myopia. Also, when the pupil dilates, spherical aberration occurs which stimulates accommodation. Adding minus power above the fitting cross of the lens solves this unique refractive condition.

When the pupil is constricted, as in daytime vision with lots of light, only the minimal amount of the central cornea is receiving incoming light rays. The very center of the cornea has fewer aberrations, and the eyes can comfortably focus light on the retina which travels to the brain where the image is formed. With lower lighting conditions, our pupils dilate and the uncorrected manifest myopia and spherical aberrations in the corneas become evident. This is the basis of how night myopia occurs, lessening the visual acuity for the wearer.

According to IOT’s clinical trials, applying the best optical solution for night myopia is to add a little bit of minus power above the fitting cross. After calculating various possibilities, the scientists discovered that adding -0.25 diopters (D) in this part of the lens is the best solution. While -0.25 D does not seem like a big deal, it is just the right amount to offset the optical challenges of spherical aberration and unwanted accommodation due to night myopia.

How do we explain this to our patients?

As always, keep the technical conversation simple and concise. Consider asking questions about night driving. Try to discern if their night driving chief visual complaint is about glare or lack of good vision. “I just do not see as well at night while driving” is a common complaint. When we hear that, we then need to further investigate if it is a glare issue or a visual clarity issue and recommend the appropriate optical solution.

Here’s an example of what you could say:

“Do you have added difficulty driving at night, either without correction or with Rx lenses with AR coatings? It is possible that you also have night myopia. It is more common than we may think. If so, try a pair of Endless Drive Progressive lenses and see for yourself. These lenses incorporate IOT Digital Ray-Path 2 ray tracing technology, which yields increased ranges of vision with the help of the eyes’ natural ability to accommodate at different distances within 20 feet.”

Our personal expertise, and especially our experience, brings added empathy and value to what we are recommending to our patients.

How great is it that we have these added specialized technologies to provide clear and comfortable vision for all types of use?

What a great time to be in optics!

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Contact IOT about adding Endless Drive to your portfolio.

About the Author: Laurie Pierce , LDO, ABOM, NCLC

Ms. Pierce is an Associate Professor in the Opticianry program at Hillsborough Community College in Tampa, Florida. Laurie is a graduate of Newbury College’s opticianary program in Boston and managed Lugene Opticians, an upscale optical boutique in Boston’s Copley Place. Ms. Pierce lectures extensively on optical theory and management topics at local, regional, and national optical conferences. Ms. Pierce is certified as an ABO Master Optician and is certified by the National Contact Lens Examiners. She has received the National Federation of Opticianry Schools Educator of the Year award and was named by Vision Monday one of America’s Most Influential Women in Optics.