DRAFT FOR CONSULTATION. DOES NOT REPRESENT OFFICIAL WHO VIEW
WHO World report on vision
DRAFT FOR CONSULTATION
Table of Contents
WHO World report on vision
DRAFT FOR CONSULTATION
Executive Summary
Preface
Introduction
Aims of the report
Chapter 1 – Understanding vision
Introduction
What is vision?
Introduction to key terms
Vision plays an important role in life
Vision problems are broader than vision impairment
Childhood and adolescence
Adulthood
Older age
Conclusion
Chapter 2 – The global situation
Introduction
Eye diseases
Vision impairment
Large numbers of people are affected by vision impairment
There have been changes in vision impairment data over time
Efforts to address vision impairment are not keeping pace with demographic changes
The number of people affected is predicted to triple
Eye diseases and vision impairment – an unequal burden
Vision impairment is closely associated with ageing
Poverty contributes to vision impairment
More women than men bear the burden of vision impairment
Changes in eye diseases over time
Vision impacts on countries as a whole
There is an economic cost to eye diseases and vision impairment
The cost of eye diseases is not yet known
Vision impairment impacts on other areas of the health system
Vision also touches other areas of development
There is a strong case to support investment in vision
Investing in vision will contribute towards achieving the Sustainable Development Goals
Conclusion
Chapter 3 – The global response – lessons learned
Introduction
Addressing common causes of vision loss
Some diseases can be entirely prevented
Other diseases can be treated to restore vision
Preventing vision loss from other eye diseases
Health promotion for vision
Vision protection
Disease-specific programmes
Quality of care
Access to services
Integration
Developing national plans and mechanism for supporting eye care
Human resources
Data and information
Vision Rehabilitation
Advocating for eye care
Conclusion
Chapter 4 - The future: comprehensive eye care services
Introduction
Definition of comprehensive eye care services
Key Elements of comprehensive eye care services
Conclusion
Chapter 5 – The drivers of change
Introduction
Planning
People-centred services
Priority package of services
Human resources
Finance
Data and Information
Leadership and governance
Equipment, medicines and consumables
Disability inclusive development is also critical
Conclusion
Chapter 6 – Agenda for action - recommendations
Introduction
Recommendations
Conclusion
Glossary
References
Executive Summary
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Preface
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Introduction
Vision plays an important role in life, at every stage of life. Despite this, vision is often excluded from health sector planning and there remains considerable unmet need for eye care services.
Vision impairment can also pervasive, affecting every aspect of a person’s life. Without vision rehabilitation, and other supports and services, people with vision impairment are often poorer and more disadvantaged than their peers.
The ageing population will have a significant impact on vision loss. It is imperative that action is taken now to mitigate future risks, as well as to better meet current needs.The need to ensure services consider eye disease morbidity more broadly is also critical. Now is also the time to set the foundation for advancing the inclusion of eye care services as a core component part of Universal Health Coverage (UHC).
WHO, its Member States and partners have a long history in eye care and there is considerable experience to draw on for future action.
WHO World reports are an important tool in providing a global picture of the challenges and opportunities facing public health and to inform national level action. The report has been written from a public health perspective. It is focused on the vision of the global population, rather than providing advice on specific clinical issues. These matters are better considered in detailed and specific technical guidelines. The emphasis on public health is also intended to provide policy advice and evidence to support decision-making at the national level.
Aims of the report
This report recognising that the opportunities provided by vision are denied to many, often because of inadequate health promotion, prevention, treatment and vision rehabilitation.
Vision is not solely the responsibility of eye care professionals nor the health sector. It connects to and impacts upon many other areas of life, such as education, employment and recreation. As such, this report is intended to provide advice and guidance for a wide range of people working both within and outside the eye care sector. This includes those involved in policy, services, advocacy and research, and from across governments, Non-Government Organisations (NGO), academia and the private sector.
- Chapter 1 outlines the fundamentals of vision.
- Chapter 2 provides an outline of the current context for vision. This includes the prevalence and impact of eye diseases and vision impairment, as well as the rationale for investing in vision.
- Chapter 3 outlines what has been done so far in eye care, some of the successes and the remaining challenges.
- Chapter 4 identifies why comprehensive eye care should be the focus of action in future.
- Chapter 5 describes how comprehensive eye care services can be achieved, including what needs to be done across the health system and to ensure a people-centred approach.
- Chapter 6 provides a summary of recommendations.
Terms and concepts used in the report are explained in the text (where possible) and included in the Glossary on page 48.
Chapter 1 – Understanding vision
Introduction
TBC
What is vision?
Vision is a broad term that encompasses all of the processes of the visual system, and all of the functions of vision.
Visual system
Images travel as light from the front of the eye (cornea) to the back of the eye (retina). These images then move through a complex set of nerves and fibres to different parts of the brain. The images are interpreted by the brain and used alongside other information (such from hearing or memories) to inform how a person moves, feels and makes decisions.
Functions of vision
Vision has seven separate functions:
- Visual acuity –how sharp or fine the images are (clarity).
- Visual field – seeing what is happening to the side when looking straight forward (known as peripheral vision).
- Contrast sensitivity – determining the contrast between objects and their background.
- Colour perception – distinguishing between different colours and the light they emit.
- Vernier acuity – the ability to discern discontinuity in a line (used for detecting patterns).
- Stereoacuity – depth perception.
- Dark adapted visual threshold – the ability to see in low light.
Insert infographics – pictures of the visual system and vision functions
Introduction to key terms
To ensure clarity and consistency, this section defines and describes some of the key terms used in the report. Where possible, other terms are explained when they are used for the first time, and a complete list is included in the Glossary.
What is vision impairment?
An impairment is when a disease affects the structure or functions of a person’s body. A vision impairment covers the visual system (structure) and the functions of vision. People with vision impairment may also experience disability if they do not have sufficient access to supports and services, and face barriers such as discrimination or inaccessible buildings or transport. This understanding is consistent with the WHO International Classification of Disability, Functioning and Health (ICF).
Insert infographic – diagram of vision impairment and disability based on ICF.There are different levels of vision impairment and these impact on a person’s day-to-day life in different ways. For example someone with moderate vision impairment may not be able to legally drive or find it difficult to read a book. People with severe vision impairment may not be able to rely on their vision to identify people they know even when they are standing next to them, so need to use other senses instead. People who are blind may not be able to distinguish the difference between light and dark.
It is important to note that no two people will have the exact same experience of vision impairment. For example, two people with moderate vision impairment may have very different life experiences depending upon the cause of vision loss, their access to quality care, rehabilitation and any barriers they may encounter.
Insert case study – stories of two people in a Low Middle Income Country (LMIC)with the same disease and level of impairment but who have very different lives based on supports/services available.There are different types and levels of vision impairment that are based on measuring visual acuity and visual field (the numbers as below).
Distance vision impairmentLevel / Visual acuity
Mild / 6/12 but equal or better than 6/18
Moderate / Worse than 6/18
Severe / Worse than 6/60
Blindness / Worse than 3/60, 1/60; or no light perception
Near vision impairment
Level / Visual acuity
Near / Worse than N6 or N6 at 40cm” with existing correction.
Moderate and severe vision impairment and blindness are defined in the WHO International Classification of Diseases(1). Issues relating to the definitions and processes for measuring vision impairment are discussed in Chapter 3.
For the purposes of this report, vision impairment will also be used as an overall term for all different types and levels of vision impairment.
What is vision loss?
Vision loss is a general term used in the report to describe all levels of vision impairment, in one eye or both (mono or bilateral). It also includes the impact of an eye disease or condition before it has reached the threshold for vision impairment.
What is vision function?
Vision function encompasses all of the functions of vision as noted above.
Vision plays an important role in life
Vision develops alongside the development of the eye and the brain and is essential for child development Vision functions develop and then mature at different ages on average, for example: dark adaption visual threshold age 6 months, visual acuity age 3 years and visual fields age 4 to 10 years(2).
From the moment an infant is born, vision plays a critical role in how they grow and develop. Recognising and then smiling or making noises at family and caregivers sets the foundation for intimacy and attachment (3). This type of communication and interaction are an important part of cognitive development.
Vision is also a catalyst in learning to move. By first seeing something interesting, and then wanting to move towards it, an infant starts to develop motor skills. Vision continues to play an important role in exploration, learning and developing hand-eye coordination (3).
In the transition from childhood into adolescence, vision is often an entry point into accessing the curriculum and educational attainment (4).In adulthood, vision continues to play an important role how people live their lives, most noticeably in work. Formany tasks (such as picking a tea leaf through to driving a motor vehicle), vision is critical in enabling people to secure and retain employment(5)(6, 7).
Later in life, visionis used to ensure the completion of everyday activities, maintenance of independence and is a factor in better overall health (8).
Vision is particularly important for communication - half of all communication is non-verbal (such as gestures or facial expressions)(9). Approximately 80% of the information from the senses comes from vision (10)
Vision problems are broader than vision impairment
There are many hundreds of eye diseases. Some are mild, do not cause loss of vision and are short lived but can cause troublesome symptoms,while others lead to total and irreversible blindness. All sectors of the population are affected, from young infants through to older people, people from high, middle and low income countries, women and men. There is a growing body of evidence showing that poverty can be both a cause and consequence of vision loss.People with vision impairment can be at higher risk of violence and abuse than their peers (11). Stigma and discrimination are significant barriers that prevent people with vision impairment from participating in and contributing to their families and communities on an equal basis with others.
Wide ranging morbidity associated with eye diseases is often overlooked. Instead, the focus has to date been on causes of vision loss based on vision impairment thresholds. While this is animportant need, it is insufficient in and of itself to inform eye care service planning that meets people’s needs.
Even though the number of people affected and magnitude of impact are significant, vision impairment is only the tip of the iceberg when it comes to vision problems. There are large numbers of people who experience vision problems but have not reached a defined vision impairment threshold. This includes diseases that do not routinely lead to vision impairment, and those that do but where the progression hasn’t yet crossed the threshold.
This section uses illustrative examples to outline the impact of diseases that do not commonly lead to vision impairment, those that do but are below the vision impairment threshold and then the impact of vision impairment itself. It is important to note that the examples provided for vision impairment demonstrate the impact where there is no vision rehabilitation and other supports and services.
Childhood and adolescence
Eye diseases
For young children, eye diseases can be difficult to detect as children may not know there is a problem or be able to adequately explain their symptoms. Eye diseases at the young age can have a particular impact on schooling.
A study from Singapore found that strabismus (where one eye looks in a different direction to the other) had an adverse effect on the quality of life of children. It also found that children often worried about what their peers would think of them, while parents were concerned about the impact on their vision (12). A study from China also found that children with strabismus were more like than those with amblyopia (known as ‘lazy eye’) to report problems in comprehension (13).
A study from Rwanda suggests that children with vernal keratoconjunctivitis experience lower levels of school attendance even though it rarely impacted on vision loss. The symptoms experienced by children where uncomfortable including itching, stinging and sensitivity to light, (14).
Vision impairment
Infants with vision impairment often need support and encouragement to understand and interact with their environment to learn how to crawl and walk. Without this, they may learn to sit or stand with their peers, but may not necessarily know how to move about to different positions as they lack the visual cues to give them confidence to move. Infants with vision impairment may become more inwards focused and miss out on the stimulation of the objects around them(3).
As they grow, children with vision impairment can develop language skills that appear to be focused more on themselves, rather than others and the world around them. This is often because their experiences can be small and fragmented, that they don’t have the same sort of perspective as other children to help develop their language. Early in life, children with vision impairment may find it more comfortable to have one-on-one interactions, including with older children and adults, rather than with groups of children (15).
At school, children with vision impairment can take longer to gain literacy and numeracy skills, particularly if they require support to learn additional skills such as Braille or orientation and mobility training. In later years, children’s learning can be compromised due to slower reading speeds, curriculum and teaching methods that are often not accessible to them (15), such as the use of blackboards by teachers. In low and middle-income countries especially, children with vision impairment may not have access to supports and services that enable them to learn alongside their peers(16).
Insert case study – personal story, the difference treatment/rehabilitation can makeAdulthood
Eye diseases
Eye diseases in adulthood are a common, but under-recognised area of health care. They are particularly important given the impact they can have on work and productivity.
Dry eye disease is very common, with a number of risk factors such as menopause and prolonged computer use. A study from the USA It also showed that it had an impact on productivity, with people with mild dry eye disease needing to take on average 8 days off work (17). A study from Japan also found that people with dry eye disease found it more difficult to perform daily activities and were less productive at work, the impact of the disease increased with severity (18)(19).