World Sight Day: October 12
World
Sight Day is an annual event that focuses attention on the global problem of
blindness and visual impairment. It aims to raise public awareness around the
world about blindness and visual impairment, and to garner support and
commitment in ensuring the right to sight for all.
The
theme of this year's event, low vision and refractive error, draws attention to
the hundreds of millions of people who are functionally blind simply because
they need spectacles. Refractive error can be simply diagnosed, measured and
corrected; yet many people in low and middle income countries do not have
access to these basic services.
Some
of these diseases, such as trachoma and river blindness, are prevalent
primarily in less developed areas of the world where there are also specific
environmental hazards.
In
many middle income and industrialized countries, three other eye conditions
have emerged as potential threats to the status of sight of their populations.
The increase of diabetes among many population groups has caused diabetic
retinopathy to be added to the priority list, while glaucoma, an eye disease
known for centuries, remains on the public health agenda due to difficulties in
its early diagnosis and frequent necessity of life long treatment. Age-related
macular degeneration (AMD) ranks third among the global causes of visual
impairment with a blindness prevalence of 8,7%. It is the primary cause of
visual deficiency in industrialized countries. An emerging important cause of
visual impairment is uncorrected refractive errors
- Cataract
- Trachoma
- Onchocerciasis (river blindness)
- Childhood blindness
- Refractive errors and low vision
- Diabetic retinopathy
- Glaucoma
- Age related macular degeneration
- Corneal opacities
- Genetic eye diseases
Magnitude
of blindness and visual impairment
Since
the estimates of the 1990s, new data based on the 2002 global population show a
reduction in the number of people who are blind or visually impaired, and those
who are blind from the effects of infectious diseases, but an increase in the
number of people who are blind from conditions related to longer life spans.
This new information underscores the need to modify the health care agenda to
include the management of the diseases that are now becoming prevalent.
Magnitude of visual impairment
Globally,
in 2002 more than 161 million people were visually impaired, of whom 124
million people had low vision and 37 million were blind. However, refractive
error as a cause of visual impairment was not included, which implies that the
actual global magnitude of visual impairment is greater.
Worldwide
for each blind person, an average of 3.4 people have low vision, with country
and regional variation ranging from 2.4 to 5.5.
These
figures - the first global estimates since the early 1990s - are the best
achievable scientific estimates of the global burden of visual impairment and
are the result of new studies carried out in nearly all WHO regions, which have
substantially updated the epidemiological data.
Distribution of visual impairment
By age: Visual impairment is unequally distributed across age
groups. More than 82% of all people who are blind are 50 years of age and
older, although they represent only 19% of the world's population. Due to the
expected number of years lived in blindness (blind years), childhood blindness
remains a significant problem, with an estimated 1.4 million blind children
below age 15.
By gender: Available studies consistently indicate that in
every region of the world, and at all ages, females have a significantly higher
risk of being visually impaired than males.
Geographically: Visual impairment is not distributed uniformly
throughout the world. More than 90% of the world's visually impaired live in
developing countries.
Note: These
articles on eyesight have been adopted from the WHO (World Health Organization
) website. For more details, log on to