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It is believed that rivers are a source of water for daily use, such as cooking and bathing. But most people don’t know that these same rivers could be a threat to one’s eyesight because they can transmit a serious eye disease that can cause complete loss of vision if one gets infected. This disease is known as ‘river blindness.’

What is river blindness?

River blindness is an infection that is spread by flies that live near fast-flowing rivers. It affects both the skin and eyes and eventually results in irreversible blindness if not identified and treated early.

How is river blindness transmitted?

When someone is bitten by the black fly, worm larvae are transmitted into the victim’s body. With time, they develop into worms that can survive for as long as 15 years. These worms then produce several microscopic larvae, called ‘microfilariae’, which circulate through the internal body system. The microfilariae eventually die, causing a reaction and severe skin inflammation and itching. When this irritation spreads to the eyes, it results in permanent sight loss.

Symptoms of river blindness

Visual symptoms of river blindness include decreased vision, eye redness, eye pain, light sensitivity, clouding of the normally clear front surface of the eye (the cornea), eye lesions and vision loss or blindness. Note that these symptoms would most likely not appear until long after the microfilariae starts dying (which is long after the disease has entered the body at its early stages). Therefore, the longer the infection, the worse symptoms become. In extreme cases, blindness is the result.

Risk factors for river blindness

The following group of individuals are most definitely at a higher risk of being infected with river blindness: People residing in the agricultural regions of Latin America, sub-Saharan Africa or Yemen, people who work or live near fast-running sources of water such as streams or rivers where blackflies are present and thrive and people who are constantly or regularly bitten by Simulium blackflies.

Treatment and prevention

River blindness is only treatable if your eye doctor detects or diagnoses it early enough. This means that the prolonged presence of river blindness in your body can cause permanent loss of one’s visual field.

You can protect yourself from the disease with these few tips:

  • Use insecticides that contain N,N-Diethyl-meta-toluamide (DEET) to keep blackflies away.
  • Avoid being bitten by infected blackflies. Wear long sleeve shirts, pants, and permethrin-treated clothing, especially during the daytime. This is because that is when the black flies are most active and move about.
  • Also, make routine eye tests a priority, especially if you are at a high risk of contracting river blindness.

Rivers are a natural source of water, especially in rural communities but we need to take precautions to prevent possible infections or ailments that can result from the presence of such rivers in our communities. Contact us for more helpful water-related eye care information.