Skip to content

Vision impairment and traffic safety outcomes in low-income and middle-income countries: a systematic review and meta-analysis

Published: 26.10.2021
Prabhath Piyasena
Victoria Odette Olvera-Herrera
Ving Fai Chan
Prof Mike Clarke
David M Wright
Graeme MacKenzie
Prof Gianni Virgili
Prof Nathan Congdon
Truck driver

Road traffic injuries are a major public health concern and their prevention requires concerted efforts. A published paper in The Lancet Global Health provides the concrete data connecting vision and traffic safety, and more specifically the impacts in Low and Middle Income Countries. An interview with the authors.

Published paper

  1. What do policy makers need to know about the links between vision impairment and traffic crashes in low and middle-income countries?  

Road traffic crashes are the leading cause of death among people aged 5 to 29 years and are a major public health issue in low and middle-income countries (LMICs). Across the world, approximately 1.3 million people die each year due to road traffic injuries. This burden is especially high in LMICs, and our review suggest that vision impairment might be an important factor. We found that, in LMICs, people with vision impairment were nearly-50% more likely to be involved in traffic crash, a relationship that is not evident in high-income countries (HICs), which are more likely to keep drivers with poor vision off the roads due to availability of successful vision screening programmes and driving licensure legislation. Policy makers need to be aware of this because there are large numbers of drivers with poor vision on the roads in LMICs and many of the drivers with poor vision who were involved in crashes said that their vision was not tested as part of the process of getting a licence to drive. 

2. How might the eye health sector raise awareness of these problems and influence change?  

There are several ways in which we could help, and we propose the following actions to improve awareness of the link between vision and traffic safety:  

  • A call to action for eye care advocacy groups – Make an appearance at regional/national transportation safety board meetings to 1) present our review findings and 2) advocate for vision assessment for licensure.  
  • Work with those involved in setting traffic-related policy to create and test novel models of care, such as on-site delivery of vision services, providing refraction and glasses for those who fail vision screening when they apply for their licence and provide information and refer to eye care service providers for further management 
  • Target the most vulnerable groups such as young drivers, women and motorcyclists etc. since evidence shows that they are more prone to traffic crashes and work with them to develop and disseminate awareness raising strategies.  
  • Raise awareness among providers of eye care services about the need for referral for early treatment of the preventable causes of vision impairment.  
  • Engagement with the media and other stakeholders, for example through national days for traffic safety and other events.  
  • Generate more robust evidence through high quality scientific research. 

 3. What surprised you about the findings?  

Focusing on LMICs has given us an entirely new perspective on the importance of vision to road safety. As well as the strong relationship between poor vision and traffic crashes in LMICs, we were surprised to find that there are such high number of road users and drivers with poor vision on the roads in LMICs and that so many of them were able to obtain driving licence without mandatory vision testing.  

4. What evidence gaps did you find and how might these be filled?  

There are several important gaps, and we suggest the following to fill these:  

1) Randomised trials to assess if there is an association between vision improvement and traffic safety outcomes.  

2) Collaboration to develop uniform definitions of traffic safety outcomes.  

3) Studies in vulnerable groups such as young drivers, women, and two-wheeled vehicles etc.  

4) Research into the association between traffic crashes and other aspects of vision function, such as contrast sensitivity, stereo-acuity, etc. 

5. What do you think are the most important areas for future research? 

We need to find ways to reduce number of traffic crashes and the injuries and deaths that they cause. This will require randomised trials of interventions to improve vision, research into ways to raise awareness of vision and traffic safety among vulnerable groups and service providers, and long-term assessment of strategies intended to improve adherence to vision-related regulations when people obtain a driving licence. It is important that the sector make an effort to attend local/national meetings/committees on road safety to advocate for the issue. This is something that both NGOs and advocacy groups can do at little or no cost. Raising awareness is key to getting the funding gates opened for both research and vision programmes.  

 6. Do you have any practical recommendations for how to integrate eye health within road safety initiatives? 

We ask the IAPB membership to get involved in the advocacy meetings and work with “IAPB’s Knowledge Hub” so we can start building knowledge base around the existing driver/traffic initiatives out there.  

At the top level, there is a need for global and national-level advocacy to formulate an action plan. This might include a new 5-year plan to align with the Sustainable Development Goals [SDGs] on integrating eye health with other road safety initiatives in LMICs. 

Major national and regional level policy changes are needed to bring eye health more fully into the regulations around who can and cannot drive a motor vehicle, which has to start with licence issuing authorities. Finally, all the stakeholders involved in traffic safety need to become engaged in making changes, including transport ministries, traffic police departments and regulatory bodies for commercial drivers.  

 7. Which countries would you highlight as having a good model for vision function assessments and road safety?  

The International Road Traffic and Accident Database (IRTAD) shows that high-income countries such as Norway and Sweden have the lowest mortality rates per 100,000 people 2.0 and 2.2 respectively, compared to LMICs (Africa 28.3 per 100,000). High income countries require people applying for a driving license to provide an ‘eyesight certificate’ from an eye care provider. In the 1990s, Sweden introduced “Vision Zero” to reduce road traffic mortality and morbidity and after its success across Europe, it’s now being implement in major American cities and we’d like to see it become even more global. In addition, without adequate eye care service provision, people with vision loss are more likely to become more isolated if they are denied ‘mobility’ but not provided with required treatment and rehabilitation. These aspects should be considered in development of models of eye care for traffic safety in LMICs.   

 On the other hand, it is noteworthy that not all HICs are as effective in vision screening prior to issuing license, as an example in the UK people need only need to self-certify that their vision is ‘good enough’ to drive a light vehicle.   

8. Is there a role for the private sector? 

Yes. Private health care providers need to get more engaged in this effort. They can help by providing solutions for avoidable blindness and vision impairment, for example by treating cataracts in parts of the world where the public sector struggles with poor capacity and low resources. Such partnerships would accelerate the reduction in the number of visually impaired road users and drivers. The private sector can also help by providing medical supplies such as spectacles. An effective public-private partnership may accelerate the implementation of such strategies, prevent traffic crashes, reduce injuries, and save lives.  

9. Did any ‘good news’ stories emerged from this research? 

The main good news is that review now provides a solid evidence base for the problems that need to be addressed. We have shown  a clear association between vision impairment and traffic crashes in LMICs for the first time. Evidence from this review has led to a large trial called STABLE, which will test whether providing glasses to myopic university students in Vietnam will improve motorcycle driving safety. It will address two on-going “epidemics” in the country – myopia and motorcycle crashes – and is the first-ever randomised trial of vision and traffic safety in an LMIC. 

Image on top: A truck driver drives wearing glasses/Sandeep Biswas