When we’re behind the wheel of the car we are looking at the road, scanning forward and side to side watching the other vehicles, watching our blind spots, checking for pedestrians and cyclists, watching for kids and balls, and of course keeping an eye out for motorcycles. Vision is our major source of information when we are driving, and what we see determines how/where we drive and react. Our vision is so important to driving that there is even a pot on your drivers licence to indicate whether you need to be wearing glasses to drive.
There are many causes for poor vision, and vision can be variable or deteriorate slowly without a person necessarily noticing a problem until they have lost a great deal of vision. Cataracts, medications, diabetes, retinal detachments, glaucoma, myopia, and corneal scars can all degrade vision. Other diseases or conditions can cause double vision. When vision is not clear, or depth perception is lost it can be very difficult to estimate where objects are on the road and to avoid them.
The way your eyes move also impacts what you see on the roadway. If you are staring at a fixed point ahead of the car you will not be able to perceive all the things on the road. Your eye’s movements allow you to see and grasp what you see on the road.
The concern is that most of the time people are not aware of eye problems. They are asymptomatic. You can lose a part of your vision and not even notice. It’s only when you see the optometrist of ophthalmologist that many eye conditions are diagnose, treated and if possible corrected. Diabetics are at particularly high risk for undiagnosed eye defects with estimates of 25% of the patients having vision loss that they were unaware of until they saw the optometrist.
A cursory vision check is required when you get your drivers licence or renew it, but this test is not comprehensive and does nothing more than check peripheral vision. There is no standard across the country for vision checks of drivers, nor is there consistent requirements for different classes of drivers.
A recent pile up on a Quebec highway resulted in several recommendations being made. These included that drivers have comprehensive eye examinations at set ages, and that vision testing requirements be standardized. These recommendations were not acted upon
An optometrist can immediately remove your licence if your vision is considered too poor to be able to drive, they can remove it temporarily if your condition is treatable. They are required by law to report anyone who is suffering from an eye condition that makes it dangerous to drive.