Driving and Glaucoma

Glaucoma Vision Loss and Driving

The National Transport Commission and Austroads have identified glaucoma as a health condition that can affect our capacity to drive safely. Therefore, it is important to be aware of how glaucoma can influence our ability to remain safe on the road.

Glaucoma can affect our vision and ability to drive in the following ways:

Visual Field Loss Show less Show more

Glaucoma can cause peripheral visual field loss resulting in reduced awareness of objects and people in our side vision. Central vision is often unaffected in the early stages of glaucoma, so our ability to see clearly is unchanged. Initial changes in the visual field are subtle but can be detrimental to our safety on the road. Often, when small areas of vision disappear, the brain fills in the image to create an inaccurate but believable scene in the part of the visual field that is diminished. This is called the “filling-in-effect” (Image 1). The filling-in-effect influences our visual perception when driving and impairs our ability to see hazards on the road such as pedestrians, bike riders, other vehicles, road debris or potholes.

Glaucomatous visual field loss can also enlarge our blindspot when driving and impede our ability to safely merge into traffic or change lanes.

Side-by-side images one showing a person crossing a pedestrian crossing the other showing the filling-in-effect caused by glaucomatous visual field loss. On the second image you can see the pedestrian crossing but not the person crossing it.

Impaired Dark Adaptation Show less Show more

Our visual field plays an important role in being able to adjust to changes in lighting conditions and manage glare. Reduced peripheral vision can hinder our ability to rapidly adapt to dynamic variations in lighting, such as when we are driving through a series of shadows cast on the road.

Difficulty to adapt to dim or dark environments can also impair our ability to manage glare from oncoming traffic at night or judge distances of surrounding cars.

Research has reported that people with glaucoma commonly choose to avoid driving at night or in poor lighting conditions due to difficulty with dark adaptation.

A busy city intersection on a dark and raining night with lights reflecting off the road

Decrease in Contrast Sensitivity Show less Show more

Contrast is our ability to see how faded an image is before it becomes indistinguishable. Glaucomatous loss can cause subtle and unconscious changes in our contrast vision. Good contrast sensitivity is important to be able to see pedestrians, other vehicles and hazards in poor lighting conditions and on overcast and rainy days.

Reduced Depth Perception Show less Show more

Depth perception is likely to become affected when there are asymmetrical changes in the eyes. Reduced depth perception can impair our ability to judge distances of moving and stationary hazards. Loss of depth perception can affect our ability to judge the distance of surrounding cars, knowing when to reduce our speed or stop, safely change lanes or merge into traffic.

Drivers with glaucoma can seek advice from their ophthalmologist, general practitioner, orthoptist or optometrist to understand their glaucomatous vision loss and the potential impact on their driving.

Driver Obligations

Mandatory Reporting Show less Show more

It is important to understand that by law, doctors and optometrists are obligated to contact the relevant State or Territory licensing authority and report patients who no longer meet the Australian Driving Standard requirements for vision.

Self-Reporting Show less Show more

Drivers are legally required to notify their State or Territory licensing authority of a serious or chronic medical condition (including glaucoma), injuries or disabilities that may affect fitness to drive. Failure to notify could affect insurance cover.

Drivers with a chronic eye condition are also required to report a change in vision or if they have a vision impairment that can impede safe driving.

Wearing Glasses and Contact Lenses Show less Show more

Drivers who are able to meet the eligibility for driving without glasses will be able to hold an unconditional licence. However, drivers who require glasses or contact lenses to meet the vision standards for driving will hold a conditional licence. The use of glasses will be listed as a condition on your licence (identified as S under conditions) (Image 2). Additionally, drivers will be required to pass a new eyesight test if they start or stop wearing glasses or contact lenses to drive to ensure they continue to meet the vision requirements for driving.

Sample VicRoads drivers licence showing conditions printed on the front and back

Assessing Vision for Driving

When you apply for or renewing a licence, you will be required to pass an eyesight test. Licensing requirements vary between states, but generally an eye care practitioner will assess your visual acuity and visual field to establish your fitness to drive.

Visual acuity is a measure of central vision and our ability to distinguish details and the shape of objects. Commonly, visual acuity is measured using a chart with different sized letters. The measurement will appear as a fraction, for example 6/12, where the numerator is the testing distance and the denominator is the measurement of acuity.

Visual Filed is the extent of side vision that we can see. Visual field tests, also known as perimetry tests, are specifically designed to assess and detect changes that occur within the normal visual field. The visual field measurement is commonly recorded in degrees, for example 65 degrees indicates vision extends 65degrees from the centre of the visual field.

The binocular Esterman visual field test is a specific test used to assess visual field for driving. The Esterman is a functional perimetry test that more intensely assesses central vision, inferior visual field and horizontal meridian. These are the areas of the visual field that we rely on most when driving. Austroads have specified that the Esterman is conducted with both eyes open, with fixation monitoring (looking straight ahead at all times) and wearing the pair of glasses used for driving, whether it is single vision, bifocal or multifocal glasses.

Visual acuity chart with different sized letters

Australian Driving Standards

Each State and Territory licensing authority will review the information reported by an optometrist or ophthalmologist who have assessed vision according to the national fitness to drive standards.

All drivers must meet the following criteria to be able to hold a drivers licence:

Visual Acuity of 6/12 or better without glasses*

AND

Visual Field without glasses*:

Binocular visual field extending horizontally 110 degrees and above and below 10 degrees

AND

No significant field loss within a central radius of 20 degrees of foveal fixation

OR

No more than 4 areas of field loss within a central radius of 20 degrees of foveal fixation

* If you require glasses to meet the requirement then this will be conditional on your licence

Additional Information

Loss of vision in one eye (monocular): Drivers cannot drive for 3 months after losing vision in one eye. After 3 months drivers must meet visual acuity and visual field criteria.
Poor night vision: Drivers may be issued with a conditional licence (e.g. no night driving)

Drivers Licence Renewal

States and Territories licensing authorities have their own drivers licence renewal system. Certain states require drivers to have regular eyesight tests depending on their age. Drivers who fail the fitness to drive criteria and lose their licence are able to follow their state or territories’ appeals process.

For further information it is best to contact your State or Territory driver licensing authority.

State/Territory Driver Licensing Authorities Contact Details

State	Authority	Contact	Website
ACT	Road User Services	13 22 81 rus@act.gov.au	www.rego.act.gov.au
NSW	Roads & Maritime Services	13 22 13 Contact.Centre@rms.nsw.gov.au	https://www.rms.nsw.gov.au
NT	Department of Transport	1300 654 628 or 08 8999 3111 mvr@nt.gov.au	www.nt.gov.au/transport
QLD	Department of Transport and Main Roads	13 23 80	www.tmr.qld.gov.au
SA	Department Planning, Transport and Infrastructure	13 10 84 DPTI.enquiriesadministrator@sa.gov.au	www.transport.sa.gov.au
TAS	Department of Infrastructure, Energy and Resources	1300 851 225 dier@dier.tas.gov.au	www.transport.tas.gov.au
VIC	VicRoads Medical Review	13 11 71	www.vicroads.vic.gov.au/medicalreview
WA	Department of Transport	13 11 56 medicalreview@roads.vic.gov.au	www.transport.wa.gov.au

Strategies to Support Safe Driving

The following strategies are to support drivers specifically with glaucoma:

Position your seat correctly and utilise mirrors and reversing cameras to minimise your blind spots.
Ensure you are well rested and alert.
Reduce your speed when driving in the rain, through fog or on overcast days to give you sufficient time to react to unexpected hazards.
Scan your environment twice before changing lanes.
Ensure there is a sufficient gap between your car and the car in front of you. A safe following distance can be achieved by using the standard three-second rule as a guide to judge the distance of the car in front.
Pre-plan unfamiliar routes using a navigation system.
Reduce your speed as you approach a turn or traffic lights.
Mute or turn off your mobile phone when driving so your attention is not compromised when you are on the road. This is particularly important when driving in unfamiliar areas.

Looking forward out a car windscreen at busy lanes of traffic ahead

Vehicle Safety Features

The following vehicle safety features reduces the risk of hazards and also improves safety of the driver and their passengers:

Electronic stability control
Adaptive cruise control
Road sign information
Distance alert
Autonomous emergency braking
Driver attention detection
Lane departure and blind spot warning systems
Rear collision warning and cross-traffic alert

Natalia Kelly, Orthoptist at Vision Matters

Article by Natalia Kelly

Orthoptist, B.Orth&OphthSc, PGDiplHltResMthds

Natalia is a registered and accredited orthoptist, who established Vision Matters, a private orthoptic practice in Melbourne. Her practice specialises in innovative vision rehabilitation with focus on paediatric and adult low vision, biofeedback training and neurological vision impairment assessment and intervention.

References

Heijl, A., Patella, V. M., & Bengtsson, B. (2020). Effective Perimetry (4th ed.) [E-book]. Carl Zeiss Meditec, Inc. https://www.academia.edu/2183305/Effective_Perimetry_Zeiss_Visual_Field_Primer_4th_Edition._Heijl_Bengtsson_and_Patella_2012_
Tam, A. L., Trope, G. E., Buys, Y. M., Yang, Y., Shen, C., & Jin, Y. P. (2018). Self-perceived Impact of glaucomatous visual field loss and visual disabilities on driving difficulty and cessation. Journal of glaucoma, 27(11), 981-986.
doi: 10.1097/IJG.0000000000001079
VicRoads. (2019, October 28). Licence Conditions. https://www.vicroads.vic.gov.au/licences/licence-and-permit-types/licence-conditions
Austroads. (2020). Assessing Fitness to Drive. https://austroads.com.au/publications/assessing-fitness-to-drive/ap-g56/vision-and-eye-disorders/medical-standards-for-licensing-11
Department of Transport Western Australia, (2020), https://www.transport.wa.gov.au/
Government of South Australia, (2020), Medical Fitness to Drive. https://www.sa.gov.au/topics/driving-and-transport/licences/drivers-licence/medical-fitness-to-drive
Vicroads, (2020), Health and Driving https://www.vicroads.vic.gov.au/licences/health-and-driving
Transport for NSW, (2020), Are you fit to drive? https://www.rms.nsw.gov.au/roads/licence/health/fit-to-drive.html
Tasmanian Government, (2020), Transport Services https://www.transport.tas.gov.au/licensing/
Northern Territory Government, (2020), Get Your Drivers Licence https://nt.gov.au/driving/driverlicence/get-your-licence/get-your-driver-licence
ACT Government, (2020), ACT Driver Licence Information https://www.accesscanberra.act.gov.au/app/answers/detail/a_id/1581/~/act-driver-licence-information
Queensland Government, (2020), Driver Licensing https://www.qld.gov.au/transport/licensing/driver-licensing

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