Without a doubt, sight is one of the most used senses. Therefore, vision loss is a serious and life-changing problem. Do you want to know what are the causes and symptoms of this problem? Read on and we will explain it to you.
First of all, for there to be a decrease in visual acuity, any of the media involved must be affected. In this sense, partial or total blindness will occur when there is a problem with the cornea, lens, retina or optic nerve.
Causes of partial blindness
When we refer to partial blindness, we are referring to those people who, despite having greatly decreased their visual acuity, they are still able to distinguish certain shapes, lights and shadows. In this way the meaning is not completely lost, but it makes its use difficult.
Depending on its origin, this type of blindness can be chronic or acute. Let’s look at the most frequent causes of partial vision loss.
corneal injuries
Any injury to the surface of a tissue will generate a scar and the cornea is no exception. This scar eliminates the transparency of the cornea, which prevents light from reaching the retina, causing a decrease in visual acuity.
Corneal injuries can have different origins, from serious infections to some direct trauma. Any stimulus that can damage the cells of the same to a considerable depth will be able to generate partial blindness.
The affected field of vision will vary depending on the location and size of the scar. In this sense, there is no specific presentation template. However, the following symptoms may occur:
- Blurred vision: or a black or dull area of ​​vision.
- Ache: with itching in the affected eye.
- Crying eyes.
- Red dots.
- Gritty feel: like having something embedded in the eye.
waterfalls
Another of the most common causes of partial blindness is cataracts. I am they are opacities in the lens, which is the primary means of refraction of the eye. This opacity prevents light from hitting the retina properly, which is why partial vision loss is generated.
In most cases they appear due to degeneration of the lens or some injury to it. Second different studiescataracts are the cause of 47.9% of blindness in the elderly.
Among the main symptoms reported by people with cataracts are stands out THE blurred, dull, or foggy vision, faded colors, and inability to see well at night. They also report lights that appear very bright or have a halo around them, as well as double vision.
retinal problems
The retina is the part of the eye responsible for translating direct light signals from the lens so that the brain processes them. So any injury can cause loss of vision.
In most cases, retinal problems are caused by faulty capillaries, which will leak fluid into the fabric. In this way, among the most common causes we can find the following:
- Diabetic retinopathy.
- Blockage of the arteries or veins of the eye.
- Retinal tear.
- Partial retinal detachment.
- Hypertensive retinopathy.
However, there is another type of retinal lesion that is not related to the presence of liquids. An example of this is the macular degenerationin which the center of the retina begins to deteriorate, leading to blurred vision or a blind spot in the field of vision.
Finish, various fungal, parasitic or bacterial infections can seriously injure him. This is the case of ocular toxoplasmosis, very common in immunosuppressed people.
Optic nerve problems
The optic nerve is responsible for transmitting all the information captured by the retina to the brain, which is why it is also an essential part of vision. Generally, problems related to this structure affect one or more fields of vision.
In most cases, they are produced by glaucoma. This is a frequent disease that generates an increase in intraocular pressure that affects the nerve. In this sense it fails to adequately transmit signals, making vision difficult.
However, there is another set of conditions that can cause partial blindness by affecting the optic nerve, such as optic neuritis or inflammation of the nerve. Also we have indirectly the effect of cerebrovascular events (CVD) or tumors in the central nervous system.
It is important to clarify that the symptoms of optic nerve lesions can vary according to their etiology. However, the people they usually present with rapid vision loss, reddish saturation in one or more fields of visiondouble vision and eye pain.
Causes of total blindness
On the other hand, we have total blindness. This occurs when a person is unable to distinguish between light and dark.. The situations that can cause total vision loss may be the same situations that cause partial blindness, however, at this point they are in their terminal stage.
Trauma or serious injury
When the trauma is very serious and affects the entire cornea, total blindness can be generated.. One of the most frequent causes of this type of injury is chemical burns.
However, not only corneal lesions are able to influence visual acuity. Head or eyeball trauma, whether penetrating or blunt, can damage the optic nerve and retina.
complete retinal detachment
We have mentioned partial retinal detachment as a cause of partial blindness. However, if not treated in time, it can progress and become a total detachment, preventing vision.
In most cases, it occurs due to the presence of fluid on the back of the retina. This it will separate the tissue from the eyeballcutting off the blood supply, which will cause ischemia and death of the area.
While it may be asymptomatic and painless at first, some people may experience the following symptoms:
- appearance of spots on the eyes.
- sudden lights in all fields of vision.
- Vision blurred.
- sudden loss of peripheral vision and after central vision.
end-stage diabetic retinopathy
Diabetic retinopathy is one of the complications of diabetes mellitus. It affects the capillaries of the retina., which will filter the liquid towards it and favor the deposit of substances. Also, some healthy blood vessels can become blocked.
Partial blindness can occur in the early stages of the disease, however, if left to progress, it causes total loss of vision. This is because in the last stage new blood vessels with very thin walls are generated to try to adequately irrigate the tissue. These new capillaries are prone to spontaneous rupture and retinal hemorrhage.
endophthalmitis
A rare cause of vision loss is endophthalmitis. It’s an infection inside the eye and should always be regarded as a medical emergency.
This infection is produced, to a large extent, by the entry of external microorganisms after surgery or eye injuries. However, it can also be caused by an internal septic infection that has affected the eye.
Among the symptoms that people with endophthalmitis present severe eye pain is distinguished by redness of the eyes and the appearance of a discharge yellow, white or purulent inside the eyeball. The eyelids are also inflamed.
vascular occlusion
All blood vessels in the body are prone to clogging. When the retina or optic nerve is blocked, there can be painless vision loss.
In the event that the affected blood vessel is the central retinal artery or the optic nerve artery, the blood supply to the tissue will be inadequate. This will generate that there is not enough oxygen supply, so he may have a heart attack. and be permanently damaged.
On the other hand, when the central retinal vein, there will not be adequate blood drainage. This will cause a puddle, that is, an excessive accumulation of fluid in the tissue, which will lead to blindness.
When to see a doctor for vision loss?
Loss of vision, total or partial, should always be considered a medical emergency. On many occasions it may not be accompanied by pain, although this does not indicate that it is less severe and, therefore, should never be ignored.
As, It is imperative to consult a specialist as soon as possible. so that he can carry out the relevant tests and arrive at an accurate diagnosis. Many of the causes give only a short time before the damage is irreversible.
It is important to clarify that when vision loss cannot be reversed, lifestyle needs to be changed. Fortunately, today there are many ways in which people with visual impairments can go about their daily activities without problems.
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