If you struggle with dry eye disease, know that you are not alone. An estimated 16.4 million Americans have been diagnosed with chronic dry eye. Because of the differences in symptoms and underdiagnosis, this number is likely much higher. Research has shown that most adults over the age of 65 have experienced some type of dry eye symptoms.1
Vision problems with dry eye can be frustrating. You know it is happening, but it may not happen all the time. One common frustration with chronic dry eye is night driving. You may struggle to see better, have blurred vision, or notice a glare to your vision while driving at night.
Understanding why this happens and how dry eye disease makes this problem worse can help you take steps to improve your nighttime driving.
The importance of tears
The tears are made up of the perfect mix of oil on water, held onto the surface of your eye by mucus. Blinking washes the tears over the surface of your eye, smoothing its rough surface. Without the moisturizing tears, the surface of your eye is not the polished lens needed for proper vision.2
Aging, dry eyes, and night driving
Normal aging changes in your eye can make both dry eye disease and night driving more difficult. As we age, the lens covering the front of the eye hardens. The muscles that surround the pupil (the small, black opening in the center of the eye that lets light in) also become weaker as we age. This makes the pupil less responsive to light.3,4
Car crashes are the leading cause of on-the-job deaths among older workers in the United States. Poor night vision may be a contributing factor.3,4
Why is my vision worse driving at night?
By nighttime, your eyes may be drier than they are during the day simply because you have used them all day. If you have strained or overused your eyes by staring at a computer screen at work or home, your eyes can be drier than usual.
For someone with normal eye moisture, the surface of your eye stays moist between blinks. This allows for easy, smooth blinking. In dry eye disease, the eye surface becomes dry and rough between blinks. This can scatter light abnormally instead of focusing it for clear vision.2
Light scattering from dry eye is especially noticeable at night because the pupil is usually dilated (open) under low-light conditions. As a result, more scattered light can enter the pupil at night compared to scattered light during the day. That is why bright, oncoming headlights can be especially bothersome when driving at night.2
What can I do to help?
It is important to see your eye doctor for regular vision exams. Using eyeglasses that are not updated with your current vision needs can put extra strain on your eyes, making driving at night worse.
Tell your eye doctor about your struggle with night driving. You may need special glasses to wear while driving at night.
Other steps you can take to help improve vision and safety while driving at night might include:5
- Keep your windshield and windows clean
- Keep your vehicle in good repair, making sure your headlights and windshield wipers are working properly
- Avoid driving while stressed or tired
- When possible, limit your night driving and stick to roads and areas that are well-lit and familiar