Night driving glasses: Help or hoax?

Glasses with yellow tinted lenses can enhance contrast in certain daylight conditions, since the yellow tint blocks some of the sun's blue light.

This high-energy visible (HEV) blue light is more likely to cause glare when it enters the eye, compared to other forms of visible light.

The "blue-blocking" filtration provided by yellow tinted lenses also occurs with amber- and copper-colored lenses.

These darker tints can block much more blue light than yellow lenses. But they also prevent more light from entering the eye, which reduces visibility even more in low-light conditions.

In fact, even yellow lenses reduce the overall visible light to a degree, since they also block some blue light. This might be a good thing during the day, but not at night — when maximum visibility is key.

Researchers at Harvard's Schepens Eye Research Institute recently conducted a study to find out whether night driving glasses provided any visual benefit for nighttime driving.

All 22 of the participants "drove" in four simulated night-driving conditions, wearing either yellow-tinted night driving glasses or glasses with clear lenses. Each participant also drove in scenarios with and without a headlight glare simulator activated, to mimic the effect of oncoming traffic.

In each scenario, participants' reaction time to seeing a pedestrian walking alongside the simulated roadway was measured.

The study found that night driving glasses did not appear to improve:

• How well participants detected pedestrians at night.

• The negative effects of headlight glare on pedestrian detection.

"Our data suggest that wearing yellow-lens glasses when driving at night does not improve performance in the most critical task: detection of pedestrians," the study's authors said.

In fact, the results found "that wearing yellow-lens glasses may slightly worsen performance," but the finding "was not statistically significant."

"These findings do not appear to support having eye care professionals advise patients to use yellow-lens night-driving glasses," the authors concluded.

Start by scheduling a comprehensive eye exam with an eye doctor. Many people who think their vision is fine are surprised to find out how much clearer they can see at night, even when a small amount of uncorrected refractive error is corrected with new glasses.

If your eyes are healthy and you don't have vision problems that need to be corrected with prescription glasses, then the best glasses for night driving are no glasses at all.

On the other hand, if you need prescription eyeglasses because you have nearsightedness, farsightedness or astigmatism, choose clear corrective lenses with an anti-reflective (AR) coating.

These lenses:

• Allow almost 100% of visible light to enter your eyes.

• Let your eyes focus properly on the road and other obstacles at night.

• Reduce or eliminate the glare-causing reflections of streetlights and headlights within your lenses.

• Offer the best possible vision for your eyes, since they're based on your individual prescription.

Some people might wonder if they should buy clear lenses with AR coating for night driving even if they have no need for vision correction. The answer is no; AR coating only reduces the glare caused by the eyeglass lenses themselves. There is no visual benefit to wearing non-prescription lenses with AR coating.