Blindness (visual Impairment): What It Is, Types, Causes And Treatment
Vision problems are one of the most common physical conditions among the general population , it is estimated that the vast majority of people suffer or will suffer from some type of visual problem throughout their lives. However, a vision problem of this type does not have to imply any degree of blindness.
There are certain criteria that to consider a vision difficulty as blindness or visual impairment Throughout this article we will talk about what blindness is, the different types that exist and what their associated symptoms, causes and treatment are.
Blindness, also known as visual impairment or vision loss, is a physical condition that causes a decrease in the ability to see to varying degrees and that causes a series of difficulties that cannot be fully compensated with the use of glasses or contact lenses.
To be more exact, the term blindness is used to define that condition in which the loss of vision is complete or almost complete.
Vision loss can come on suddenly or develop gradually over time. Besides, vision loss may be complete or partial ; That is, it can affect both eyes or only one respectively. It may even be partial because it only affects certain parts of the visual field.
The range of causes that can cause vision loss is extremely varied and ranges from those that directly affect the eyes to those that involve the brain’s visual processing centers.
Besides, Vision deterioration tends to become more common as we age the most common risk factors being the appearance of physical conditions such as glaucoma, diabetic retinopathy, age-related macular degeneration or cataracts.
According to data from the World Health Organization (WHO), it is estimated that 80% of visual disability is preventable or curable with treatment, including those caused by cataracts, infections, glaucoma, uncorrected refractive errors, and certain cases of blindness. children, etc.
In all other cases, people with significant or total blindness can benefit from vision rehabilitation programs, modifications to their environment, and assistive devices.
Finally, in 2015 data, there were 246 million people in the world with low vision and 39 million people diagnosed with blindness. Most of these people are in developed countries and are over 50 years old, but this may be due to the lack of data in developing countries.
Types of visual impairment
There are different types of visual impairment depending on the degree of impact on the ability to see. This significance can involve anything from partial vision to complete blindness or visual impairment. The World Health Organization (WHO) developed the following classification of the different types or degrees of visual impairment
To measure the degree of disability, vision in the best eye, with the best possible lens correction, is taken into account. Taking this into account, the classification is as follows:
In addition, depending on the specific vision conditions, visual impairment can also be classified as follows:
To better understand these terms, it should be noted that visual acuity consists of the resolution with which we see. That is, the ability to perceive and differentiate visual stimuli. While the field of vision is the extent observable at any given moment.
Finally, legal blindness or extremely poor visual acuity is considered as such when the person has a visual acuity of 20/200 , even after lens correction. There are a large number of people diagnosed with “legal” blindness who are able to distinguish shapes and shadows but cannot appreciate their details.
And night blindness?
A very little-known type of blindness is night blindness, also known as nyctalopia. This type of blindness is a condition that causes great difficulty or inability to see in relatively little light.
It can also be described as an insufficient adaptation of vision to the dark and can be a symptom of various eye diseases such as retinitis pigmentosa, retinal detachment, pathological myopia or a side effect to certain medications such as phenothiazines, among many other causes.
Causes of visual impairment
There are many common causes of the appearance of visual impairment and blindness. However, the incidence of these varies considerably between the two conditions. The main causes of visual impairment at any degree can be:
Existing treatments
There are some treatment options that can help correct vision defects and minimize possible further degeneration. The choice of one of these treatments will depend on the following considerations:
Possible treatments or aids for managing both visual impairment and blindness include:
