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What are some common causes of blindness?

Blindness is a condition in which a person is no longer able to see or even tell the difference between light and darkness in both eyes. However, it may also refer to severe decline of eyesight, which leads to visual impairment. In this case, even with the use of medicine, contact lenses or eyeglasses, an individual cannot see well or at all.

According to researchers, about 300 million people throughout the world suffer from blindness or visual impairment. At least 50 million of these individuals are completely blind, and about 80 percent of cases of blindness may be observed in the elderly or those over 50 years old.

Blindness: What are the Symptoms?

Visually-impaired individuals have gone through a range of symptoms before they turn totally blind. Moreover, vision loss can vary from one person to another, and there are instances when the symptom progresses at a fast rate that a person eventually loses vision later in life. Some individuals are born blind, while others lose vision suddenly, and there are those whose condition worsen over a few years.

Some symptoms linked with blindness include sensation of having a foreign body in the eye, discomfort, discharge and pain in the eyes. These signs, however, depend largely on the underlying cause of visual impairment.

Causes of Blindness

There are numerous causes of blindness, and these range from traumatic injuries or accidents, complications from disorders and macular degeneration. Based on statistics, it was observed that 90 percent of visual impairment cases in third-world countries are attributed to glaucoma, cataracts and injuries. As for underdeveloped nations, blindness is caused by leprosy, onchocerciasis and trachoma.

It is also worth noting that blindness may occur due to retinopathy of prematurity, diseases of the blood vessel that involve the optic nerve, retinitis pigmentosa, hereditary eye diseases or vitamin A deficiency. Chemical poisoning can also cause blindness, particularly when one is exposed to methanol, which is a highly toxic element.

Below are key facts about some of the common causes of blindness:

1)  Glaucoma

This type of eye disease can cause serious damages to the optic nerve, which is responsible for providing visual information from the eyes and into your brain.  However, once a high amount of pressure is present inside the eye, glaucoma may occur. With this intense pressure, the optic nerve tissue may suffer from damages that will eventually progress to blindness or loss of vision.

An acute-angle closure type of glaucoma is considered as a medical emergency, which requires prompt treatment to prevent complications. Among the symptoms linked with this condition are nausea, sudden blurred vision or vision disturbances, vomiting, severe eye pain and redness in the eye. Seeing colored rings or halos around lights is another common sign of this eye problem.

As for the primary open-angle type of glaucoma, there are no symptoms at all. However, you will experience a gradual loss of vision that eventually leads to blindness. Hence, it is important that you consult an eye specialist to have any changes in vision properly monitored.

There are several causes of glaucoma. These include reduced flow of blood to the optic nerve, high blood pressure, dilating eye drops and medications. The intraocular pressure or IOP (natural pressure in the eye) may increase once the cornea and iris channels are obstructed or blocked.

As the IOP further increases, damages to the optic nerve may arise. This condition will cause loss of sight in the affected eye. Furthermore, vision loss due to glaucoma is not possible to be restored, and there is no cure for this eye disease.

2)  Diabetic Retinopathy

Diabetics who suffer from damages in the retina’s blood vessels are predisposed to a condition called diabetic retinopathy. Common among those who have either type 1 or 2 diabeties, the condition may begin as a mild vision problem that progresses into total blindness. In fact, diabetics who go blind have this condition.

Having too much sugar in the blood can lead to diabetic retinopathy. High blood sugar level causes damages to blood vessels in the retina, along with excessive blood pressure. Once there is a blockage in the blood vessels, partial blindness may occur. New blood vessels that fail to form properly only leads to scar tissues, which result to vision loss.

Symptoms of this condition include night blindness, seeing dark spots or floaters, problems with distinguishing colors, blurred and loss of vision. Your chances of having diabetic retinopathy also increases the longer you are suffering from diabetes. So, by managing this medical condition, the progression of developing loss of vision can also be slowed down.

3)  Retinal Vascular Occlusion

Another cause of blindness, although quite rare, is retinal vascular occlusion. This disorder affects the retina. When there is a clot or blockage in the vessels that supply blood to and from the retina, an occlusion forms. This condition can also worsen among people who suffer from atherosclerosis, which is typical among obese and elderly individuals.

While the particular cause of blood clots or obstructions in the retina is still unknown, there are certain risk factors to retinal vascular occlusion. These include heart problems, atherosclerosis, blood clots, high cholesterol, glaucoma, macular edema, rare blood disorders and diabetes.

Complications of this disorder include visual impairment, particularly due to macular edema and proper supply of oxygen and blood to the retina. Retinal detachment may also occur, although this is a very rare condition.

Final Word

By being aware of the causes of blindness, you will have a better understanding of how to properly care for your eyes through a healthier lifestyle and diet. Also, be sure to consult your eye specialist if you suffer from problems with your eyes including blurred vision, headaches and other issues that affect your eyesight.

April 2017
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