The lens is a part of the eyeball, functioning as a double-convex, transparent lens that is 4mm thick and 9mm wide, surrounded by a semipermeable membrane for water and electrolytes. The lens has the function of adjusting so that images from external objects, whether near or far, can be properly focused on the retina.
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| The cause of cataracts is a result of oxidation due to insufficient oxygen supply (Photo: benhammersley) |
If the lens becomes cloudy, it is similar to a foggy glass that obscures the view outside. When the lens becomes completely opaque, it will prevent images from reaching the retina, leading to blindness. Cataracts are one of the leading causes of blindness worldwide and in Vietnam, predominantly affecting individuals over 50 years old. The condition progresses slowly, initially presenting as a decrease in presbyopia due to the onset of myopic adjustments; exposure to bright light will cause discomfort but not pain. As the condition worsens, vision appears as if viewed through a layer of cloudy glass, seeing a fixed dark spot against a bright background until complete vision loss occurs.
Causes of cataracts are a consequence of oxidation due to insufficient oxygen supply, increased water content, and decreased protein levels. Specific factors contributing to cataracts include exposure to sunlight, artificial light (stage lights, studio lights, high-intensity lamps…), exposure to viruses, bacteria, environmental toxins, and smoke (from cigarettes, vehicles, factories…). This exposure can potentially damage the protein components of the lens, leading to a gradual loss of protein and resulting in cataracts.
A diet rich in antioxidants and good liver function can help prevent the disease. Individuals with cataracts tend to be deficient in vitamin C, copper, manganese, and zinc. Antioxidants present in the lens, such as glutathione along with coenzyme vitamin B2, can protect the eyes. Preventing cataracts requires stopping smoking and consuming a variety of antioxidant-rich foods such as carrots, lentils, onions, garlic, spinach, cabbage, bean sprouts, and fresh legumes and seeds.
