How does your vision impact your mobility?
Clear vision is critical for a safe driving or cycling experience. Even a minor vision impairment — or a distraction — can reduce your reaction time when every split-second matters to prevent an accident.
How does your vision impact your mobility, your safety on the road, bike path or sidewalk? Let us count some of the ways:
Up to 80% of all vision impairments can be prevented, corrected or treated. Talk to your optician about how you can keep your vision sharp for a safer, more comfortable drive, ride or walk.
- BLINDING GLARE: Whether you are biking to work or driving into the sunset, the glare from bright sunlight can make it very difficult to see clearly. Sunglasses with 100% ultraviolet (UV) protection (also called UV 400) can help.
- BLURRY VISION: Do road signs seem blurry at a distance? Uncorrected vision problems (such as nearsightedness) make it hard for drivers to read highway exit signs and for pedestrians and runners to read signals at street crossings.
- FUZZY DASHBOARD: If you are hyperopic (farsighted) or presbyopic, you may have difficulty focusing on the dials and gauges on your car’s dashboard, some of which require frequent monitoring.
- DELAYED REACTIONS: School children dash into the road. Other cars swerve into your lane. Broken glass on your bike path leads you to steer sharply to the right or left. Seeing clearly — and reacting quickly — can avert accidents.
How do you know if you need glasses as a road user?
Do you squint or strain your eyes to see when you are behind the wheel or scootering your way through the city? You may need glasses to see clearly all that’s ahead of you.
Blurry, unfocused vision is a symptom of all four of the most common and easily-correctable-with-glasses eye conditions: shortsightedness, farsightedness, astigmatism and presbyopia.
You are definitely not alone. As many as 1 out of every 5 drivers (which means billions of people worldwide) cannot see the road clearly because of uncorrected vision issues.
Here’s a closer look at how some of these common vision conditions can affect your road safety:
SHORTSIGHTEDNESS: Road signs in the distance appear blurry. How can this be a problem? If you can’t read the exit marker until too late, you’ll either cut over sharply (endangering yourself and others) or take the next exit and circle back.
FARSIGHTEDNESS: Are you nearly out of petrol? Are you driving too fast? It may be difficult to read those dials on your dashboard. The road safety ramifications are obvious in this case: You may be stuck on the side of the lane or ticketed for speeding.
With astigmatism, objects at near and far distances may look blurry.
With presbyopia, often called age-related nearsightedness, you will begin to have difficulty focusing on dashboards and other close-up objects starting around age 40.
The solution for each of these vision problems is a pair of glasses. See your eye care professional for an eye exam and prescription.
Get the glasses you need to be able to see clearly out your windshield (to safely exit the highway) and to make out your dashboard dials (so you aren’t surprised to hear a siren behind you).
Should I wear sunglasses while driving, biking or riding?
Yes! Wearing sunglasses on a clear, sunny day is a great way to increase safety and comfort while you’re driving, biking or cycling.
Sunglasses provide 100% protection from ultraviolet (UV) rays and, by greatly reducing sunlight brightness, sunnies (or shades, if you prefer) give you one less visual distraction while you’re cruising on the motorway or zipping along the cycle path.
Sunglasses — both prescription and non-prescription varieties — shield your eyes from the sun. If you already wear glasses, prescription sunglasses are your best choice. If you have perfect vision or wear contact lenses, sporting non-prescription sunnies outside is just smart.
There are sunglasses for all sorts of sports and hobbies, too. Competitive cyclists have sunglasses that allow them to swap out lenses for various sun and weather conditions. For drivers, polarised glasses can help reduce blinding glare.
On long drives or rides, reaching for sunglasses can mean taking your eyes off what’s in front of you for a moment. That can be dangerous. That’s why photochromic lenses are another option to protect your eyes.
Photochromic sunglasses (such as Transitions lenses) are like three glasses in one — the lenses are clear indoors, darken outdoors in sunlight and offer protection from the sun’s rays outside and blue light inside.
However you choose to shield your eyes, you’re riding off into the sunset (or sunrise or the bright of the day) in safety.
How does drinking impair your vision as a driver?
There’s a reason you should never drink and drive: Alcohol can significantly impair your ability to see clearly, think quickly and react accordingly. This means driving under the influence makes you a danger to yourself and everyone else on the road.
There are small muscles in the eyes constantly working to focus our vision. Alcohol affects muscle coordination, and these eye muscles are no exception. As more alcohol is consumed and visual focusing becomes more impaired, people will experience increasingly blurred and double vision — especially dangerous when operating a vehicle.
Alcohol can also increase dry eyes, decrease peripheral vision (resulting in tunnel vision) and reduce the ability to differentiate between varying contrast levels.
Driving starts with vision, and impairing this sense can have a domino effect on other parts of the body. Since cognitive performance and judgment also become impaired as alcohol consumption increases, these visual effects can be dangerously underestimated.
How safe are older drivers?
The European Road Safety Observatory (ERSO) notes that preconceived notions about elderly drivers being unsafe are not necessarily true, and that driver safety “depends on the physical and mental condition of the individual.”
Ageing eyesight is noted by ERSO as one of the main physical traits that make older drivers more vulnerable.
ERSO has determined that “elderly drivers are more likely to hurt themselves than to put others at risk,” largely due to the physical vulnerability that comes with age. They found drivers over age 75 have 2 times the injury rate and 5 times the fatality rate as the average driver. These rates are roughly 3 to 7 times higher than the previous age group: drivers aged 65-74.
In addition to refractive errors like presbyopia, which are more easily treated, untreated cataracts also add risk to driving. Drivers with cataracts are 2.5 times more likely to have previously been in a crash and take an extra 0.35 seconds to react on the road. At 130 kilometres per hour (around 80 miles per hour), this fraction of a second adds 12 meters (almost 40 feet) to stopping distance.
Maintaining an up-to-date eye prescription and getting help for treatable vision ailments ensures a safer journey for the elderly and anyone else they encounter on the road.
Are there glasses for driving that correct both near and far vision?
Yes. Varifocal lenses correct near, far and intermediate-distance vision. The intermediate section covers anything that falls between the near and far focal lengths.
Varifocals place near and intermediate viewing toward the bottom of each lens, while the far segment takes up roughly the top half. This suits driving particularly well, since the dashboard sits in front of you at the bottom of your visual field, while the road ahead sits naturally in the top portion of the lens.
Varifocal lenses have a smooth transition, giving the appearance of a single, uninterrupted lens and providing a more youthful look. And you can avoid the pesky image jump you get with bifocals and trifocals, which comes from moving your eyes over the hard lines between focal areas.
While it may take a little time to get used to seeing through different magnifications in a single lens, the benefits of having one pair of glasses to suit all your visual distancing needs will far outweigh the minor inconvenience of any adaptation period.
Annoyed by glare from sunlight? What are the solutions?
We’ve all experienced the sun’s glare — at sunrise, sunset or any time in between. It can be annoying, but also hazardous. Sunglasses are the best way to protect yourself while maintaining a full field of vision.
Sunglasses, particularly those with polarised lenses, help reduce the strength of the sun’s glare while you’re driving. Polarised sunglass lenses are designed specifically to block the part of the light spectrum responsible for glare and reflections, leading to improved comfort, contrast and clarity on sunny days.
By reducing daytime glare, polarized lenses improve a driver’s reaction time by up to 0.3 seconds, according to the Association for Research in Vision and Ophthalmology. Removing 0.3 seconds while travelling at 130 kilometres per hour (about 80 miles an hour) reduces stopping distance by up to 11 meters (about 36 feet). At 80 kilometres per hour (about 50 miles per hour), stopping distance is reduced by 7 meters (about 23 feet).
This can be the difference between an accident and a near-miss in many situations.
What type of glasses should not be worn when driving?
There are five categories of sunglasses (levels 0-5) and each let in a different amount of light. Level 0 glasses block little to no light, while categories 1 through 3 block increasing amounts. Most sunglasses fall in either category 2 or 3, either one of which is safe for daytime driving.
Category 4 sunglasses allow less than 10% of light to pass through and should not be worn while driving. Police in some countries will even ticket drivers wearing category 4 sunglasses. As a general rule, if your glasses are too dark to see through, don’t wear them when you drive.
Glasses that automatically darken under the sun’s UV rays are called photochromic or Transitions lenses. These are a great option for combining glasses and sunglasses into a single pair, but they may not always be the best option for intense sunlight that causes blinding glare. Polarised lenses reducing blinding glare for comfortable vision during daytime driving.
Because most windshields block UV rays, regular photochromic lenses often remain clear in the car. So, if you’re interested in using these lenses for driving, make sure to get the kind specifically designed for use in the car. This way they’ll be sure to reduce glare and give your eyes relief from the sun’s bright light.
Do driving glasses and driving sunglasses really help?
Yes — glasses specially designed for daytime driving will include an anti-reflective (AR) coating that reduces haze and glare during the day. They have the capability to lessen the amount of image “ghosting” caused by reflections on the surface of the eyeglass lenses themselves.
While most AR-coated lenses do not include UV protection — you need a special lens tint or coating for that purpose — most car windshields are designed to block UV radiation. However, this doesn’t replace the need for sunglasses — even with UV protection from your windshield, you may experience discomfort from bright sunlight when you drive during the day.
Sunglasses for driving
If you opt for sunglasses when driving (prescription or not), look for polarized lenses to reduce glare and display objects more clearly on bright days. Polarised lenses block the specific form of light responsible for sun glare, meaning you can have a safer, less distracted driving experience during daytime hours.
When driving, polarised lenses can also improve reaction time by up to 0.3 seconds. A 0.3-second advantage in reaction time while travelling at 130 kilometres per hour (around 80 miles per hour) shaves 11 meters (around 35 feet) off a car’s overall stopping distance.
Under certain circumstances, that extra time and stopping distance may be enough to avoid a disaster.
When do you need glasses to drive a car or ride a motorbike?
While there usually aren’t direct prescription laws for driving or riding, there are general ways to convert each area’s requirements.
In the United Kingdom, for example, you must be able to read a car number plate in daylight from 20 meters away — about five car lengths — either with or without glasses (or other correction).
In an eye test, visual acuity of 0.5 (6/12) is required in both eyes, meaning you must be able to read at 6 meters away what a person with “normal” vision can read at 12 meters away. This equates to about 20/40 vision, two “steps” below 20/20 vision (6/6 in the UK).
In the eye prescription of a nearsighted person, 20/40 vision is represented by a diopter value of -0.75. Dioptres are usually listed on your prescription under “Sphere” or “Power.”
Nearsighted people with dioptre values of 0.00, -0.25 or -0.50 have at least 20/30 vision and are not legally required to wear glasses. While 20/20 vision isn’t legally required, it will always provide the greatest driving safety.
Other parts of your prescription can be more difficult to decipher — people with astigmatism are one example. Additionally, testing requisites for farsightedness (long-sightedness) or presbyopia can vary.
An optician will be happy to verify whether your vision meets the legal requirements for driving in your country.