Having trouble seeing while driving at night? You’re not alone

Have you recently noticed more vision problems passing other cars while driving at night? It is likely not your imagination or your eyesight worsening with age.

Many Americans have reported similar issues, and factors such as larger vehicles and headlight misalignment are partially to blame. But the most significant aspect is a change in the headlights themselves causing eye discomfort and pain for other drivers.

In some sense, nighttime driving has always been difficult for some people. The reasoning has to do with a person’s pupils, the round openings in the center of each eye, said Dr. Joseph Allen, an optometrist and host of the Doctor Eye Health YouTube channel with more than 1 million subscribers.

Pupils widen in the dark, a feature Allen compared to a “survival mechanism” that allows a person to detect movement more easily. The downside, he explained in one video, is it causes a loss of “depth of focus,” meaning an object’s edges will be slightly blurred even if the item itself is clear.

A sudden burst of headlights from an oncoming car can cause the pupils to rapidly constrict, leading to a brief but painful sensation. And while an unexpected flash of light is never particularly pleasant, modern cars are often equipped with lights that result in even more discomfort for drivers.

Older car headlights generally contained halogen lightbulbs that produced a yellowish color before switching to LED lights that give off white or blue hues in the past 20 years or so. According to Allen, research has shown that the newer headlight colors are more triggering to our neurological system even when the brightness between them and the halogen bulbs is the same.

“I think personally they should probably be made illegal in some way,” the optometrist said of the LED lights. “When I see them, they not only are bothersome visually, like I can’t see, but they cause almost a physical pain inside my eye.”

Another key factor contributing to the headlight problem is the increasing size of cars. A Business Insider story, citing data from J.D. Power, said the number of new SUVs and trucks sold in the U.S. jumped from 53% in 2010 to 79% in 2021. The larger vehicles mean headlights are set higher, often shining directly in drivers’ faces as opposed to older models set below eye level.

In addition, the headlights in many vehicles may not be aligned properly — and there are very few regulations in place to address it. According to an NBC news article from May 2023, only 10 states check headlight alignment as part of annual or biennial vehicle inspections.

As a result, many headlights are either tilted upward into the eyesight of other drivers or pointed in different directions.

For the safety of others on the road, Allen recommends motorists check with a mechanic to ensure their car lights are properly aligned to point straight out and down.