1. What is Cataract?

Cataract (also known as lens opacity) is a common eye disease, especially in older adults. The lens is a transparent, biconvex structure that plays a crucial role in allowing light to pass through and focus correctly on the retina.

The refractive power of the lens is essential for the eye's optical system, ensuring that distant images are focused correctly on the retina. The ability of the lens to change thickness, known as accommodation, helps the eye focus on nearby objects.

When the lens loses its transparency, it becomes cloudy, making it difficult for light to pass through. This results in blurred vision, reduced eyesight, and in severe cases, blindness.

According to the World Health Organization (WHO), approximately 18 million people worldwide are blind in both eyes due to cataracts. In Vietnam, cataracts account for 66.1% of all cases of blindness in individuals over 50 years old.

2. Signs and Symptoms of Cataracts

Cataracts develop gradually but can be detected through the following abnormal signs:

• Blurred vision and unclear images: Patients experience blurry, hazy vision, making objects appear less sharp than before.
• Foggy or cloudy vision: It may feel as though a thin layer of fog is covering the eyes, making it difficult to see clearly.
• Yellowish or faded colors: Cataracts often cause colors to appear dull and faded, with a yellowish tint, reducing the vibrancy of objects.
• Sensitivity to light, glare, and double vision: Patients may experience glare when exposed to bright light, or they may see double images, making daily activities and driving challenging.

However, these symptoms can also be associated with other eye conditions such as refractive errors, macular degeneration, glaucoma, or uveitis. As a result, early signs of cataracts are often mistaken for other eye issues, leading to delayed diagnosis and treatment. This increases the risk of disease progression and potential complications.