Astigmatism

Astigmatism is a common refractive error caused by an irregular curvature of the cornea or lens, which prevents light from focusing evenly on the retina. As a result, individuals with astigmatism experience distorted or blurred vision at all distances, both near and far. Unlike myopia (nearsightedness) or hyperopia (farsightedness), where vision is affected at specific distances, astigmatism affects the clarity of vision across all ranges.

• Causes: The primary cause of astigmatism is an uneven shape of the cornea or lens, which can be either naturally occurring or the result of an eye injury, surgery, or certain diseases. A perfectly shaped cornea or lens is spherical, like a basketball, but with astigmatism, it is more like an oval, causing light to focus on multiple points on the retina rather than a single one.
• Symptoms: Common symptoms of astigmatism include blurred or distorted vision, eyestrain, headaches, and difficulty seeing at night. In some cases, individuals may squint or tilt their heads to try to improve their vision. Children with undiagnosed astigmatism may experience learning difficulties due to poor vision.
• Treatment: Astigmatism can be corrected with glasses, contact lenses, or refractive surgery, such as LASIK. Toric lenses, which have different focusing powers in different meridians, are commonly used to correct astigmatism. In more severe cases, specialized contact lenses or surgical interventions may be required to correct the corneal shape and restore clear vision.