The Right to Sight is the global initiative for the elimination of avoidable blindness, a joint programme of the World Health Organization (WHO) and the International Agency for the Prevention of Blindness (IAPB).
VISION 2020: The Right to Sight was launched in 1999. It sought to promote:
“A world in which nobody is needlessly visually impaired, where those with unavoidable vision loss can achieve their full potential.”
The Global Initiative was set up to:
“Intensify and accelerate prevention of blindness activities so as to achieve the goal of eliminating avoidable blindness by 2020.”
It sought to do this by:
“Focussing initially on certain diseases which are the main causes of blindness and for which proven cost effective interventions are available.”
The VISION 2020 Global Initiative has subsequently been complemented and built upon by a series of additional plans. In 2006 VISION 2020 stakeholders developed an action plan for the period 2006-11, which extended the remit to focus not only upon the elimination of avoidable blindness, but to include visual impairment – particularly that caused by uncorrected refractive error.
In addition four World Health Assembly resolutions (2003, 2006, 2009 and 2013) have reinforced the aim and objectives of VISION 2020. The last two resolutions were accompanied by WHO Action Plans which have provided more detail on how the objectives were to be achieved as well as refining some of the implementation approaches.
The most recent action plan “Universal Eye Health: A global action plan 2014 – 2019" (GAP) was unanimously adopted by Member States at the World Health Assembly in 2013 as part of WHA resolution 66.4. This latest plan has an overall vision that restates that of VISION 2020: The Right to Sight whilst adding a further dimension around “universal access to comprehensive eye care services.”
The GAP also sets itself a Global Target of “Reduction in prevalence of avoidable visual impairment by 25% by 2019” (compared to the baseline prevalence of 2010). This is now seen as a more realistic global target as to what can be achieved by the end of this decade, rather than the original VISION 2020 target of global elimination by 2020. Some individual countries may achieve, or be close to, elimination by 2020.
The long-term goal of both the GAP and VISION 2020 remain the same – to rid the world of avoidable blindness and visual impairment. It is a shocking fact that in the 21st Century there are still some 285m visually impaired and blind persons and that 80% of these cases could have been prevented or treated.
VISION 2020 has made a huge difference to global eye health and has been able to create a major focus in the countries and districts where action is needed.
Awareness of the VISION 2020 brand remains strong and the aims, aspirations, principles and approaches that were at the heart of the original Global Initiative remain in place to this day
LOW VISION Telescopes
Low-vision devices are designed to improve visual performance in children with low vision, thus enabling academic and social adaptation and providing enrichment of daily experiences. They can be optical or optical and electronic.
Types of Devices Optical
When conventional lenses do not provide required visual range, aids that have optical properties capable of promoting better visual performance through lenses are indicated.
Types of optical aids for
- Intermediate distance
Optical Aids for Distance and Intermediate Distance
The telescopic system (TS) or telescope is an optical instrument that improves the resolution of an object by increasing the size of the image projected on the retina, making it closer. . It is available for far, near, and middle distances
Figure 1. Telescope for distant view.
A telescope enables greater participation in daily and social activities such as watching television and reading white boards, street signs, house and building numbers, billboards, and menu boards. On the other hand, restriction of visual field and illumination, difficulty in locating and focusing on objects quickly, and limited focus depth are disadvantages of the telescopes. Telescopes are not universally accepted due to expense, difficulty in using the devices, and asthetic considerations. Good coordination and training are essential.
Types of Telescopes
- Galilean or Keplerian
- Hand-held, spectacle-mounted, or clip-on
- Monocular or binocular
- Fixed focus, focusable telescope, or autofocus
Figure 2. Telescopes for distance, near, and middle distance.
The Galilean telescope is a simple system consisting of 2 lenses:
- Objective lens: convex (plus) lens, closest to the object
- Ocular lens: minus lens, closest to the eye
The distance between the 2 lenses is determined by the difference in their focal lengths. The image produced is real and erect. It's lighter, shorter, and cheaper than the Keplerian type, thus the first-choice prescription for children. It is also the first choice in cases of peripheral field loss; in these cases, the lens order is designed in reverse (plus lens closer to the eye), providing a wider visual field.
Also known as astronomical or prismatic, the Keplerian telescope is an optical system that uses 2 convex (plus) lenses, the objective lens being of smaller diopter power than the ocular. The distance between the lenses is the sum of their focal lengths. The image is real and inverted, requiring a prism to reverse the image, making it longer and heavier. It produces greater visual field and better optical quality than Galilean type and costs more.
Hand-Held, Spectacle-Mounted, or Clip-On Telescope
A hand-held telescope is simpler, lighter, and cheaper than the Galilean and Keplerian types. It is particularly indicated for short activities and could be a first prescription choice for children (Figure 2).
A spectacle-mounted telescope leaves the hands free. It is useful for prolonged activities and activities that require visualization of details. However, they both weigh and cost more
The clip-on model has the advantages of both: It is lighter than the spectacle-mounted model, however, it can scratch the lenses and reduce the visual field to further distances.
Monocular or Binocular
A monocular telescope is indicated when there is a significant difference in visual acuity (VA) between the 2 eyes. It is more discreet, lighter, and cheaper. It can be used in the dominant or better-seeing eye. Binocular telescope is indicated when there is similar VA in both eyes, with the purpose of increasing the visual field, and for nystagmus. The binocular style both weighs and costs more than monocular (Figure 2)
Fixed-Focus, Focusable, or Autofocus Telescope
A fixed-focus telescope is indicated for children with poor motor coordination. Nowadays it is rarely prescribed; a focusable telescope reaches far, near, and intermediate distance and is preferred for and by children. The autofocus telescope both weighs and costs more and it does not constitute the first choice prescription for children.
Low Vision Rehabilitation Helps the Legally Blind To See Again
As strange as it may sound most of the people labeled as being blind still have some sight left. Thanks to the developments in the field or rehabilitative vision, this small left vision can easily be made use of to improve or ease daily life. It is very important to understand the fact that anyone withlow visionisvisually impairedand hence subject to many problems ranging from minor to severe difficulty. Keep in mind, at the moment, there are two general classifications oflow visionin use today. These are partial and legal blindness.
It is also very important to understand the fact thatlow visiontakes many forms and exists in varying degrees. This being the case, it is very important to understand the fact that the visual acuity alone is not enough to predict the degree of the problem. Below is also an overview of the types of commonlow vision:
- Low of central vision- it makes it difficult to read or even recognize faces and details in the distance.
- Loss of side vision-it majorly affects mobility and slow reading since the person only gets to see a few words at a time.
- Blurred vision-it makes objects both near and far seem out of focus.
- Generalized haze- the sensation of a film or glare seems to extend over the entire viewing field producing patterns of relatively severe vision loss.
- Extreme light sensitivity- it exists when the standard levels of illumination overwhelms the visual system and as a result producing a washed out image. For people with extreme light sensitivity, pain and discomfort can be experienced.
- Night blindness- it is the inability to see outside at night under starlight or moonlight.
Depending on what you settle for, it is important to understand the fact that yourlow vision rehabilitationsolution should be advised by a specializedVision Rehabilitation Therapist.
Low Vision Devices Providing Hope for the Visually Impaired
Are you having trouble seeing properly enough to read? Are you having trouble watching TV or writing checks? Well, if yes then you may need to see a low vision rehabilitation specialist and also get to understand the fact that: these are simple some of the daily tasks which stand to become very difficult with low visionor better yet vision loss. It is important to understand the fact that even though these conditions with the eyes are not treatable, there are several solutions to making them better for instance video magnifier and that there is hope.
Perhaps there might not be a cure for your eye disease but there are certainlylow vision devices which can help you to do some of the things which your limited sight may otherwise not allow you to do. It is important to understand the fact that most eye diseases usually do not result into total blindness. This is because there is most often some useable sight remaining and which is enough to regain independent living skills once proper magnification or illumination is brought about. Simply put, you are not visually impaired if you have some usable vision.
Looking back, telescopes and strong magnifiers were by far the only tools which the visually impaired had access to. Although these older devices are still useful, at the moment, there are countless obstacles for those with limited sight. For instance, when magnification is increased, the field of view is greatly reduced. This effect is clearly evident when using binoculars. Magnification can either be increased or reduced plus at the moment there are low vision doctors who recommend low vision rehabilitation and other tools to individuals which low vision. Remember, most of the standard devices which are recommended by low vision specialist are very helpful in making the condition better hence the reason you are advised to consider them.