The eyes control most of your movements and decisions while driving. With good vision and visual comfort you can drive safely by maintaining concentration. Daylight vision problems are usually worse at night, increasing the risk in driving.
Many motor vehicle accidents are caused by drivers’ poor vision. According to most parties involved in an accident, the other driver “must have been blind”.
Let’s look at some of the possible causes of these accidents:
- The driver’s vision is below the recommended standard. He could have a visual deficiency such as nearsightedness, farsightedness or astigmatism. Cataracts could also affect the driver’s vision.
- Failure to wear spectacles or contact lenses where they have been prescribed for distance use.
- Low visibility due to darkness or adverse weather conditions, including extreme heat.
- Driving too fast. The normal field of vision is 180°. At 95 km/h the field of vision is only a quarter of its normal size. This means that the faster you drive, the less you see to the side.
- Glare in the driver’s eyes.
- A dirty windscreen.
- Distraction of driver from either inside or outside the vehicle.
- Reduced mental alertness because of fatigue, alcohol, drugs, boredom or general physical condition.
More than 90% of information used in driving comes through the eyes. Make sure that your eyes are healthy and receive adequate care. There is a constant need to be able to distinguish objects clearly when driving. If vision is below standard the motorist becomes a safety hazard to himself and to others. You owe it to yourself and others to have your eyes examined professionally once a year to maintain optimum eyesight and driving vision.
How to use your eyes in driving
Safe driving involves:
- Visual acuity
This is the ability to focus and see clearly with both eyes, individually as well as together. With good acuity you will see detail very easily. In the case of drivers it is particularly vital in identifying road signs, cyclists, pedestrians and animals. Peripheral vision This is the ability to see over a wider area without moving either the eyes or the head, sometimes called “looking out of the corner of your eyes”. It refers to your total field of vision.
- Depth perception
This is the ability to judge space and relative distance between objects or between an object and the vehicle. Depth perception depends on good binocular vision, essential for judging whether a car can be passed safely in the face of oncoming traffic and when moving from one lane to another among moving vehicles.
- Night vision
This is the ability to see in the area of low illumination beyond your headlights, to see in the presence of the glare of oncoming headlights and to recover quickly from its effects. Night vision deteriorates with age and older drivers with reduced vision will need to exercise greater care when driving at dusk and at night and should have proper driving spectacles.
