Everything You Need To Know About Visual Impairment
Visual impairment generates limitations in various fields. It is a prevalent problem in the world population, but today there are more and more technological aids.
According to data from the World Health Organization (WHO), in the world there are around 2.2 billion people with some degree of visual impairment. Of these, about 1 billion could have prevented this condition if they had been treated in time and in the right way.
The institution also points out that visual impairment is more recurrent in rural areas, in low-income sectors, in women, in the elderly and in ethnic minorities. This corroborates the link between this problem and the difficulty or impossibility of accessing an adequate approach in time.
What is visual impairment?
There is no absolute consensus on the concept of visual disability. This is because there are still differences regarding the border that separates the impairment from the disability as such. However, one of the most assumed meanings is the one that we will share with you below.
It is noted that the expression “visual impairment” should be used generically to cover both people who are totally blind and those who have significant impairment. In this way, it is a concept that covers any type of serious visual problem, regardless of the cause that causes it.
In this regard, the concept is complemented by noting that said problem must generate limitations to carry out certain activities, such as reading, writing and orientation and mobility. In turn, blindness is understood as any form of serious visual impairment, without implying a total absence of vision.
What are your causes?
The main causes of visual impairment and blindness are cataracts, ametropia, trachoma, onchocerciasis, glaucoma, diabetic retinopathy, and age-related macular degeneration. Let’s see in more detail:
- Cataracts: they are considered the main cause of blindness in the world. It is estimated that they correspond to 43% of cases and are due to a loss of transparency in the lens.
- Diabetic retinopathy: it is the main cause of vision loss in developed countries. It is typical of those who do not control blood sugar levels. It progresses to progressive blindness from small bleeds in the eye.
- Age-related macular degeneration: second cause of visual impairment in developed countries. In principle, it causes a blurred central vision, but if it progresses it can turn into blindness.
- Glaucoma: it is responsible for around 15% of cases of visual impairment in the world. It leads to loss of peripheral vision due to an increase in the internal pressure of the eye.
- Trachoma: it is an infection that affects both eyes and is the main cause of infectious blindness. It is more common in developing countries.
- Ametropia: This term includes myopia, hyperopia and astigmatism. It is the inability of the eye to form an image of an object, due to a disproportion between the length of the eyeball and the power of its internal lenses.
- Retinitis pigmentosa: in this case, peripheral vision and the ability to see in the dark are reduced. It includes several chronic eye diseases of genetic origin.
Detection, degrees and types of visual impairment
Vision abnormalities are detected in consultation with the optometrist or ophthalmologist. Likewise, difficulty in reading, seeing up close or far, capturing images clearly or the presence of conjunctivitis or suppurations should be consulted.
There are four degrees of visual impairment, based on the acuity of the person’s eyeballs:
- Mild: visual acuity less than 50%.
- Moderate: less than 33%.
- Severe: degree of visual acuity less than 10%.
- Blindness: the values recorded in the exam are less than 1%.
On the other hand, from a functional and often legal point of view, the classification is as follows:
- Partial: when there is one eye severely affected or both eyes are partially affected.
- Total: even with loss of vision in both eyes, a visual acuity of 0.1% or more is achieved.
- Absolute: if visual acuity does not exceed 0.1%.
The needs of a person with visual impairment
A person with visual impairment can use different aids to better cope with their condition. For orientation and mobility outside the house there are canes, guide dogs and, currently, technological tools such as GPS, with applications designed for those with vision problems.
To visualize objects and, depending on the degree of visual impairment, it is advisable to help yourself with greater lighting or with devices that have enlarged fonts, magnifying glasses and high-power glasses. When blind, Braille is a very effective method of reading.
For obvious reasons, the home must be adapted to the visual conditions of each person. Likewise, today there are increasingly effective aids, such as the augmented reality electronic viewer and the so-called smart glasses .
