Night Driving Glasses
The first question a patient will often hear when they sit down in the exam chair at their eye doctor’s office is, “have you noticed any change or problems in your vision?” Having problems with vision at night is definitely within the top 10. I hear statements like, “I’m having a hard time seeing at night. I really don’t like driving anymore because of it.” Unfortunately, our eyes seem to take a back seat when it comes to active health maintenance, but there are many ways that we can improve our vision, night time vision included. Just like any other health topic, you will find solutions that sound too good to be true, some outrageous, and others that have been accepted to be true but not entirely certain as to why. Night driving glasses seems to fit that bill. We have all seen those yellow glasses being sold in stores and online. They show before and after photos of magically brightening up the darkest road. I wanted to speak on the misconception, how it really works, conditions that could cause decreased night vision and what we can do to improve this ability.
Common features that you will see on night driving glasses are “specialty” polarized lenses that improve color and clarity, anti-glare coating that reduces glare (never could have guessed that!) and a yellow tint that also reduces glare and sharpens vision. All these combined somehow magically “turns night into day.” I will often encourage patients to use some of these features based on their lifestyle and complaints, but the only add-on (anything I can add to a clear lens to make it better for the patient) that I would recommend for clearer night driving is a non-glare coating.
How does it works?
I now want to explain what each feature does so as to explain why we should be cautious when thinking about purchasing night glasses. Each of these features do work to improve certain problems that we encounter every day, so I do not discredit the technology, just on how they are advertised. On this section, I’ll get a little sciency, so if you are not into that, then just skip over to the next.
1. Polarized Lenses – Polarized lenses work by blocking light in a specific direction. Light radiates in all directions, which is why lights get dimmer the farther away it is. Now think of a piece of paper with a small slit cut in the middle of it, and you can only see through the paper in the direction of that slit. A polarized lens is made up of many tiny little slits oriented in the same direction, so the light that gets through a polarized lens is an organized beam of light oriented in the same direction as the slits. A fun fact is that if you take 2 polarized lenses and put them together, you will eventually not be able to see through the two lenses if you rotate them. The slits of the polarized lenses are perfectly 90 degrees from each other. Our cellphone screens are also polarized, so if you want to see if your sunglasses are polarized, then look at your phone with your glasses on and rotate your phone. If your phone turns black, then you have polarized glasses.
2. Non-Glare Coating – Non-glare coats are just what they seem, they block glare from light that bounces or reflects off the lenses. When you wear glasses, light from all around you will bounce off of your lenses and shine into your eyes. This is what an anti-glare coating limits. If you look at a lens without glare protection, you will see white light reflecting off the lens, while a lens with glare protection will usually have a greenish tint to it. Sometimes it can be purple or blue if it is designed to protect you from computer glare. One color is seen because the coating allows every wavelength of visible light (or every color) through except for the color reflected. This prevents most of the reflected light from distracting us, and allows for more light to enter your eye. In low lighting situations, this is a very good thing!
3. Yellow Tint – When you tint glasses you are choosing to prefer that color above all other colors. So if you have yellow glasses, which is on the longer wavelength of the visible spectrum, then you start diminishing the shorter wavelengths like blues and greens. This is what often gets the credit for providing better contrast. The reason is the center of our vision (the area that we use to read or see fine details) is made up of light receptors that work best at longer wavelengths (reds and yellows). Sounds good right? Well, don’t forget about the rest of the eye. The other 98% of the eye is dedicated to side vision or our security system of the eye. It’s not made for detail. It’s made for motion. If something or someone is moving within our peripheral vision we will notice it because of this area. The receptors here are most sensitive to shorter wavelengths like blues and greens. This area is also very sensitive in low light environments, so if we use a yellow tinted lens, it may provide better contrast, but it will also limit our security system or motion sensor, which does not sound like a great idea when driving at night.
What Causes Decreased Night Vision?
There are many conditions that can cause decreased night vision. One of the most common conditions is macular degeneration. This condition slowly destroys our center vision or the area dedicated to details and reading, but generally, it affects the amount of time it takes for our light receptors in our eyes to regenerate. For example, when walking from a bright room into a dark room, it takes time for us to start seeing objects so we can start navigating around the room again. This length of time gets longer and longer as this condition progresses. Other conditions that also decrease our night vision are glaucoma, cataracts, diabetes and many more. Nutrition and diet plays a huge role in our vision, which I will explain next.
I will always recommend seeing your eye doctor, Optometrist or Ophthalmologist, to be sure that your eyes are in top condition. Only your eye doctor can determine if you have any conditions that may affect your vision as opposed to just needing glasses. So do driving glasses have any merit or are they just a scam? It all depends on when you use them. Yellow tinted,
polarized glasses with a non-glare coating are awesome for day time use, especially during raining or foggy situations. It cuts through the glare that decreases our vision in these environments, but remember, the sun is still up providing enough light to use the tinted lenses safely.
If you truly want to see better at night, living a healthy lifestyle is the best medicine you can take. A supplement that improves night vision is Carotenoids. Carotenoids are pigments found in dark leafy greens (spinach and kale) and red fruits and veggies (carrots, tomatoes, red and orange peppers), and our eyes use these pigments to help with our night vision and also blocks harmful UV rays from the sun. You can find Carotenoid supplements at your local vitamin shop, and sometimes your eye doctor will carry them in their office.
Night vision problems are a real issue that we all have dealt with or will eventually deal with in the future. If you can only take one thing away from all this, remember, the better you take care of your overall health by healthy eating, regular visits with your primary care doctor and your eye doctor, you will help to keep your vision at optimal performance. Driving glasses work best during the day and are great during foggy or rainy conditions. If you need better nighttime vision, then speak to your eye doctor to give you the best options that fit you and your lifestyle.