…a Safe Car Is Nothing
Research shows us 60% of road accidents can be attributed to impaired vision.
Vehicle drivers and car manufacturers have become very focused on safety, and rightly so.
Most are concerned about their car’s abilities but don’t think about the major influential factor in crashes: human error especially if reaction time reduced due to poor focusing.
Vision standards need to be met in the relevant eyesight test set by the respective driver licensing authorities to avoid trouble seeing eg pedestrian crossings, road signs, speed bumps or cyclists.
Acoustic Vehicle Alerting Systems (AVAS) ideally should be fitted to all hybrid and electric vehicles.
Private vehicles,Cars, Motorcycles, Light Trucks, Buses and Trucks
A person is not fit to hold an unconditional licence if the person’s uncorrected VA is worse than 6/9 in the better eye, or worse than 6/18 in either eye.
• A conditional licence may be issued where this is met with corrective lenses.
• Taxi Drivers are not licensed by the RMS but by the Department of Transport, but the same standards apply.
If an observer has 6/6 (or 20/20 ) vision the 6/6 letters can be resolved at 6 metres ( ie identify direction of random E’s ) whereas eg 6/12 vision (poorer vision) means only the larger 6/12 letter can be resolved at 6 metres.
Similarly poorer still vision 6/30 vision eg means only the 6/30 size letters or larger can be resolved at 6 metres.
Buses and Trucks
A person is not fit to hold an unconditional licence if they have any visual field defect.
• A conditional licence may be granted subject to evidence from an optometrist or ophthalmologist that the following conditions are met:
1. Binocular visual field has an extent of at least 140 degrees within 10 degrees above and below the horizontal midline.
2. No significant field loss/scotoma, hemianopia, quadrantinopia likely to impede driving.
3. Field loss is static and unlikely to progress rapidly.
Typical uses of these fields and no of points threshold tested include
Nasal step 50° 104
No tint should ever be used at night as the eye relies on maximun light for night visual discrimination.
Anti-reflection coated prescription lenses can significantly improve night driving vision and drivers response time as the contrast of bright lights from oncoming cars can highlight noticeable halo or starburst reflections diminishing visual acuity.
The best option for night time driving is a pair of spectacles with clear lenses and an AR coating. The AR coating is beneficial in two ways. First, it minimizes internal reflections within the lenses, reducing halo problems, and second, it increases the transmittance of light through the lens to the eye. However, it is important to note, if a patient does not normally wear spectacles, AR coated lenses, or any other type of night driving glasses will not improve night vision, as AR coatings only minimize aberrations that are inherent in ophthalmic lenses and night driving glasses will simply serve to introduce those abberations to the wearer’s vision.
Transitions lenses can be Multicoated, but not tinted as it may damage the photosensitive coating
Transitions lenses except for drivewear are only activated by UV radiation, obviously the sun is the biggest source but there are other sources including computers, cameras, arc welders etc so in summary any source that emits radiation will affect Transitions. Headlights, unless they emit UV, they have no effect.
Ultraviolet light has a shorter wavelength than ordinary light and is invisible to the human eye. However, when ultraviolet light is reflected in certain materials, it is returned on longer wavelengths and becomes visible. This phenomenon, known as fluorescence, makes objects more visible and therefore offers a large potential for improving safety which is why research in the use of UVA headlamps to enhance night time visibility is ongoing.
Night time driving is one of the motorist’s most difficult tasks. The risks of having a night time accident on the road is 2 to 3 times greater than during the daytime due to visibilty issues from older Halogen/Filament Bulbs or newer HID/Xenon lamps and LEDs.
Tips for optimal night time driving vision:
– Make sure eyes are examined regularly
– Always wear an up-to-date prescription
– Lenses worn should be clear with an AR coating
– Ensure lenses are clean
– Ensure windshield is clean
– Ensure headlights are clean and properly aligned
DRIVING ASSESSMENT AND RETRAINING
In NSW, the RMS is responsible for ensuring all drivers are medically fit to drive. The law requires all licensed drivers to report directly to the RMS any long term or permanent medical condition that is likely to affect their ability to drive.
Failure to report and choosing to drive may put lives at risk and may result in serious legal and financial consequences,
including loss of insurance cover.
Driver trained and certified Occupational Therapists can arbitrate in equivocal cases eg those with a superior quadrant loss to the left will be more affected driving in Australia than those with upper right quadrant loss, due to placement of the interior rear-vision mirrors being in that upper left quadrant.
RMS may pending a medical and vision report suggest you undertake an OT (Occupational Therapist )driving assessment to
determine if the medical condition impacts on your ability to drive safely and legally.
The assessment occurs in a dual controlled car with a qualified driving instructor and the driver trained
OT. This may be in an automatic or manual car, depending upon what you are used to driving or what
your medical condition requires.
Possible Outcomes of an OT Driving Assessment:
There are a number of recommendations that can result from the assessment. These include:
At times a person may be issued with a learner’s licence in order to complete the driving assessment or
To drive legally with specialised vehicle modifications a person must have the modifications endorsed on their licence. They will be required to undertake an RMS Disability Driving Test to prove competency and safety driving with the modifications;
Occupational Therapy Australia NSW has a list of driver trained OTs throughout NSW, both hospital based
and those OTs in private practice.
Contact details are:
Phone: (02) 9648 3225
Email: [email protected]