Issues with Night Driving?

One of the most common issues we hear from patients is difficulty with night driving. If this sounds like you, then read on to learn more about what may be causing this issue and what you may be able to do to help.

In the Dark

Vision is just the processing of light. The less light, the less quality we can expect. This, unfortunately, gets exacerbated when there are extreme points of light in a field of darkness (headlights from oncoming cars). So is all hope lost? Not necessarily. Let’s talk about how we can control the controllables. The first two are things you can do without stepping foot in our office. After that, we’ll need to roll up our sleeves a bit more.

The Windshield Factor

Some of the difficulty with night driving comes from increased glare from points of light. Therefore, a lot of what we’re aiming to do can be described by the following adage; Reduce the glare, improve the vision. The first step is to make sure your windshield is as clean as you can get it – INSIDE AND OUT. The inside gets forgotten about from time-to-time and this can be a major factor in glare. I took the photo below in my truck one morning because it was such a great example this principle:

The left of the green line is where I had cleaned the inside of the windshield and the right is where I… well, it was a busy day. In normal light, it’s imperceptible. But with a point of light ahead of me (in this case, the sun), the glare becomes apparent and problematic. At night, when headlights and other points of light are ahead of you, this grime can cause a lot of the visual difficulty you’re experiencing. Cleaning the WHOLE windshield, inside and out, is a big first step. Obviously a “do as I say, not as I do” sort of thing.

Pupil Size

In dim conditions, our pupils dilate to allow a maximum amount of light in. A drawback here is that a lot of peripheral light rays enter the eye can cause more glare. If you can reduce the pupil size, you can improve your night vision… sort of. If dilated pupils = more glare/more light, then smaller pupils = less glare/less light. Meaning, your vision will be dimmed with smaller pupils. For some, the decreased glare is a step forward, but the dimmed vision is 2 steps back. But to test this for yourself, you can try an over the counter drop called Lumify. The purpose of Lumify is to make the white of your eye whiter. But a side effect of Lumify is smaller pupils. Put a drop in each eye 5-10 minutes before driving at night and you may notice an improvement. This can also be done with a few prescription strength medications, but you’d need to come in and see Drs. Shaver or VanAusdal to discuss that.

Which brings us to the next portion of our discussion on improving night driving. The things you can do that need to be discussed in-office.

Talk to Your Doc: Lenses and Prescription

• Eyeglasses. They’re the cute little windshields of the face. And what do we do with windshields? That’s right! Clean the inside and outside. Dirty, streaky lenses will cause the same glare effects as a dirty windshield.

• Are they clean, but scratched or hazed from being in the sun? Those defects can catch the light and bend it improperly, causing glare. Even a perfect prescription drops in performance when the lenses are in disrepair. If your lenses are worse for the wear, it is likely time to get them updated.

• Speaking of prescriptions, an out of date pair of glasses can cause glare, haloes, and starbursts. This can be particularly true for those with moderate to high amounts of astigmatism. Our doctors can get your optimal prescription dialed in to reduce these effects.

• The coatings you get on your new lenses can also make a big difference. Anti-reflective coatings will reduce glare and help improve your visual experience at night. Our recommendation is to go with Crizal Prevencia or Crizal Sapphire 360 UV.

Zeiss DriveSafe Lenses

Another option is the Zeiss DriveSafe lens. In a section above we talked about how pupil size affects vision, night driving in particular. The Zeiss DriveSafe lens uses this concept to its advantage with their Luminance Design Technology. This allows for optimized vision in low-light conditions.

In addition to Luminance Design Technology, the DriveSafe also employs the Duravision DriveSafe Coating. This coating is specifically designed to reduce glare from street lights and oncoming traffic, resulting in what one study showed as a 64% reducing in glare ¹.

What About Yellow Tinted Glasses?

There exists a prevailing theory among many patients that yellow tinted glasses help improve vision for night driving. Although some patients may swear by the effect of yellow tinted glasses, studies show they are not effective. In fact, one study suggests they may give the wearer too much confidence on the road. This study showed yellow tints did not improve headlight glare or pedestrian detection ². Coupled with the idea that yellow tints can actually diminish vision for those with cataracts, we do not recommend yellow tints for driving at night.

Cataracts and Other Eye Conditions Affecting Night Driving

Speaking of cataracts, they are a primary cause for glare at night and may cause enough glare that the patient refuses to drive at night. However, other ocular health abnormalities can also play a role. Dry eye, macular degeneration, corneal conditions like keratoconus, and a host of others can cause light scatter in the eye, which increases glare. A comprehensive exam with Drs. Shaver and VanAusdal can rule out major eye health abnormalities that could be giving you issues with driving at night. Recall again that vision is simply the processing of light. The less light there is, the more difficult it is to have good, crisp vision. Add extreme points of light (i.e. headlights), and glare makes the situation worse – even under the best conditions with the healthiest eyes. So while there is no silver bullet, we can at least control the controllables to give you the best possible experience with your vision at night.

To learn more about what we can do to help you, call today and make an appointment. 480-656-7739.

1. Glare Test Hella result showed that in 64% of tested subjects the DuraVision DriveSafe coating resulted in less discomfort glare than compared to ZEISS premium AR.

2. Hwang AD, Tuccar-Burak M, Peli E. Comparison of pedestrian detection with and without yellow-lens glasses during simulated night driving with and without headlight glare. JAMA Ophthalmol. August 1, 2019