Our annual “fall back” time change that gives us an extra hour of sleep is welcome news for most of us. But there are some unintended consequences of darker evenings, especially for drivers. According to the National Safety Council, traffic death rates are three times greater at night than during the day.
In a special rebroadcast of the Healthy Vision with Dr. Val Jones show, I interviewed Dr. Christina Schnider, Senior Director, Professional Communications for VISTAKON® Division of Johnson & Johnson Vision Care, about common nighttime driving problems such as dry eyes, headaches, and eye fatigue. I also spoke with John Ulczycki, Group Vice President – Strategic Initiatives, for the National Safety Council, about safe driving tips. You can listen to the show here:
Most people experience a drop in visual acuity in the dark, and this can cause difficulty seeing traffic signs, pedestrians and roadside objects. The primary reason why it’s difficult to see at night is that our pupils dilate to let in as much light as possible. The trade off with large pupils is that visual acuity suffers. It’s normal for the average person’s visual acuity to drop from 20/20 to 20/40 in low light conditions.
Because of vision challenges, driving in low-light conditions can fatigue the eyes and head and neck muscles as the driver strains to see the environment more clearly. Dry eyes can occur from reduced blink rates and motor vehicle heating and cooling systems. Glasses wearers may have a reduced field of vision which further complicates driving in the dark. In fact, in a recent survey one -in-three drivers reported that they didn’t see well at night.
Dr. Schnider and Mr. Ulczycki suggest that night time driving may be safer (and more comfortable) with these tips:
1. Update your eyeglass or contact lens prescription(s). Since darkness reduces visual acuity, wearing lenses that correct your vision to 20/20 in normal light conditions is extra important. Old glasses or contacts with outdated vision correction power can make driving in the dark more hazardous. If you experience significant challenges seeing at night, you may have a condition called “nighttime myopia” and should visit your eye doctor for advice.
2. Avoid driving long distances in low-light conditions. Since we already know that driving in the dark can cause eye fatigue, dry eyes, and reduced visual acuity, it’s best to minimize the time you spend behind the wheel during dark hours. Whenever possible, plan your travel so that the majority of your driving time occurs during daylight hours.
3. Take frequent breaks. Even though it’s tempting to push through your fatigue and finish driving those last miles to your destination, it’s safer to give yourself (and your eyes) a break. Stopping for gas or at a rest area may improve your alertness and visual fatigue. Remember that impaired drivers are more likely to be on the road at night, so vigilance on your part may prevent an accident.
4. Decrease your night-time driving speed. If you do need to drive in the dark, doing so more slowly may prevent accidents. Traveling at a slower speed can improve reaction time under lower-visibility conditions.
5. Check your headlights. It is estimated that 50% of all motor vehicle headlights are not optimally aligned. Potholes and bumps in the road can jolt the lights out of alignment. It’s important not to look directly at oncoming headlights. This can temporarily blind you as your pupils adjust to a quick change in lighting conditions.
Normally, my vision is better than 20/20. (20/15 is mine, which always prompts my eye doctor to say “Oh, you should be a pilot!” and then I laugh my face off because, really, do you know me, lady?) I’m lucky not to wear glasses or contacts at this point in my life, especially considering that everyone else in my family needs a little visual help at this point.
I’m grateful that my vision is excellent most of the time, despite a few diabetic retinopathy issues. But for the last 48 hours, it’s been a little dodgy, and managing diabetes while my eyesight is impaired has been challenging. Yesterday was the worst day for this latest relapse of the ol’ corneal abrasion, so my vision was very limited in the affected eye (and the other eye was swollen in a lovely, compassionate response to its friend’s injury, so basically I look like I’d been tagged in the face with a baseball – twice.).
My Dexcom graph was next-to-impossible to read. Read more »
In a recent interview with the president of the American Optometric Association (AOA), Dr. Dori Carlson, I learned the surprising statistic that about 1 in 4 school age children have an undetected or undiagnosed vision problem. School vision screenings, while helpful, still miss more than 75% of these problems. And for those kids who are discovered to have a vision problem during a school screening, upwards of 40% receive no follow up after the diagnosis. Clearly, we need to do better at diagnosing and treating childhood visual deficits. My full conversation with Dr. Carlson can be listened to below:
Dr. Carlson told me that the solution involves Read more »
Yesterday, I presented the case of a woman with double vision and ptosis and challenged you all to a game of “spot the lesion.” To be honest, I found this stuff impenetrable as a medical student and it was only by sheer force of will that I was able to commit it to memory for exactly long enough to pass a test on it before immediately purging it from my memory. I did this several times for various board exams and such, but it never really “stuck.” Hated neuro beyond words, I did.
As mind-numbing as I found it all in the abstract, I get excited about these cases in application. I may not remember where exactly the internal capsule is or what it does, but when I see someone with an interesting neuro deficit due to a lesion there, all of a sudden it makes so much more sense, and is, dare I say it, cool. I know, kinda sad.
This case is as classic (and cool) as you will ever see. It’s a complete palsy of the Oculomotor Nerve (CN 3 for those keeping score at home).
As I write this post, I’m wearing my new Superfocus glasses. I was given the glasses by the company to demonstrate, and they are nothing less than remarkable. I’ve used them mostly in two very common settings for me—indoors and outdoors. In both situations, they performed very well.
Superfocus lenses work by mimicking a young, healthy human eye. Each lens is actually a set of two lenses (flexible and firm). The flexible, inner lens has a transparent membrane attached to a rigid surface, sandwiching a small amount of clear fluid. The bridge (across the nose) connecting the lenses allows you to adjust the shape of the flexible lens. Slide the tab along the bridge to find the exact correction for the particular user. The intent is to achieve clear, undistorted vision within any lighting or distance.
You can learn a great deal from the Superfocus website about the benefits of adjustable lenses, how to obtain the glasses, and so forth. I won’t reiterate information from the website, but rather discuss how I have used these glasses and discuss their performance based on my own experience.
First, I used them during my work in the E.R. as a physician. Read more »
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