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Wearing yellow glasses while driving at night might make you think you are seeing better, but tests in a simulator have shown that drivers wearing them don’t spot pedestrians any faster than those wearing clear glasses.

In reality, the yellow glasses reduce the amount of light entering the eye and thus what people can see at night, says Alex Hwang of Harvard Medical School.

“It’s like wearing sunglasses during the night-time,” he says.


Yellow glasses designed to reduce the glare of the headlights of oncoming vehicles have been sold since the 1950s. The theory is that because blue light gets scattered more, filtering it out reduces glare. Such glasses are often advertised as improving night vision, and eye-care professionals commonly advise their use.

However, simple vision tests have shown these glasses actually reduce visual acuity in low-light conditions, says Hwang. To see how they affect the performance of drivers in typical night-time conditions, his team kitted out a driving simulator with a high-intensity LED array that can match the brightness of actual vehicle headlights.

Twenty-two people aged between 21 and 80 did eight driving sessions of about 10 minutes in the simulator. They were asked to sound the horn whenever they spotted a pedestrian crossing the road.

Some people think yellow glasses can improve vision getty

Those wearing yellow glasses – the study used three makes sold commercially – actually responded a fraction of a second later than those wearing clear spectacles. The difference wasn’t statistically significant but Hwang thinks repeating the study with more participants would confirm that the yellow glasses slow reaction times.

The findings show that even if blue light is scattered more, filtering it out doesn’t help night drivers. “Whatever the colour of the glasses, it is cutting off light,” Hwang says.

What was striking is that the volunteers all thought the glasses did help, saying the night scenes looked brighter. That means wearing yellow glasses might make people overconfident, he says.

Why yellow creates this illusion isn’t clear. It may that be because yellow is associated with daytime, the glasses trick people into thinking a scene is better lit than it really is.

Journal reference: JAMA Ophthalmology, DOI: 10.1001/jamaophthalmol.2019.2893