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Driving and your Eyes – The Importance of Clear Sight

  • Drive Safe-Tips/Guides-Safety

Vision and visibility – The former refers to your ability to see, and the latter refers to the state of which an object can be seen. Two extremely important factors when driving on the road, not only for the act of navigating the streets but an important safety factor.

Spectacles and blurred background
Photo by Josh Calabrese on Unsplash

The effect of poor eyesight on driving

It is common knowledge that 90% of driver information is visual, which means that a large percentage of critical decisions that drivers make are based on sight. Statistics have shown that most road accident occur due to driver error and a high percentage of those accidents are a result of poor eyesight.

  • Up to 90% of the information needed to make safe decisions while driving comes through your eyes.
  • Nearly 1 in 4 drivers cannot see clearly, yet 80% of vision impairments can be prevented or treated.
  • Driving at just 48kph with impaired vision can require an extra 3 seconds to recognise and read road signs.
  • Drivers with unaddressed cataracts are 2.5 times more likely to be involved in an accident.
  • Fatal car accidents are 2 to 4 times more likely to happen at night.
  • A study conducted in India found that 81% of drivers who had at least one visual defect were involved in some sort of accident.

What is the minimum eyesight standard for driving?

When driving, your visual acuity and field of vision (visual field) are two of the most important factors for driving safely on the road. This is why an eye test is so important when applying for your learner’s or driver’s licence. The eye test uses the Snellen chart which consists of a number of rows starting with larger alphabets from the top and gradually decreasing in size towards the bottom.

To qualify for a car driver’s licence in South Africa, you need to meet the minimum eyesight standard according to the Snellen rating. The minimum is a visual acuity of 6/12 (20/40) for each eye and a visual field of 120 degrees is needed to safely operate a vehicle. If you need prescription lenses in order to pass this eye test then this must be declared on your driver’s licence.

Night-time driving and glare

Driving in the dark requires you to focus and concentrate a lot more than when driving in daylight. Naturally, your visibility is significantly lower, but there is also the added challenge of glare from streetlights and oncoming headlights. Glare in your eyes can be temporarily blinding and put you in danger of a collision.

While glaring headlights can happen to all drivers at night, seeing halos or starbursts around lights could be due to other eyesight issues of varying levels of severity. This can range from something as simple as an incorrect lens prescription to a condition as serious as a cataract. If you’re required to drive regularly at night and are experiencing symptoms, it’s worth having your vision checked and corrected as soon as possible.

In the meantime, take extra measures by improving visibility for night driving:

  • Ensure windows and both windshields are thoroughly cleaned inside and out.
  • Keep your headlamps and clean to ensure proper lighting on the road ahead.
  • Get your headlamps checked with your regular vehicle service to ensure bulbs are in proper working order.


Vision for safe driving doesn’t start and end with a visual acuity test. As a driver, any compromise on your vision will affect your reaction time, depth perception, peripheral vision, and night time vision. This means ensuring your rear view mirrors are properly adjusted, your windscreen is clear, there are minimal distractions in your view, and not driving under the influence of any substances that may affect your senses, particularly your eyesight.

Read next: Know Your Blind Spots

Brought to you by Supa Quick to mark World Sight Day on 14October. Find your nearest store and pop in for a free vehicle safety check.

Disclaimer: This content is for informational, educational, or entertainment purposes only. We do not make any warranties about the completeness, reliability, and accuracy of the content.


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