What is astigmatism in optics?

Astigmatism is a common optical condition where the eye cannot focus light evenly on the retina.

Astigmatism is a type of refractive error that affects the way the eye focuses light. In a normal eye, the cornea and lens are smooth and evenly curved, allowing light to be focused precisely on the retina. However, in an eye with astigmatism, the cornea or lens is irregularly shaped, causing light to be focused unevenly on the retina. This can result in blurred or distorted vision, particularly at certain distances or angles.

Astigmatism can be diagnosed through a comprehensive eye exam, which may include a visual acuity test, a refraction test, and a keratometry test to measure the curvature of the cornea. Treatment for astigmatism typically involves corrective lenses, such as glasses or contact lenses, that compensate for the uneven curvature of the cornea or lens. In some cases, refractive surgery may be an option to reshape the cornea and improve vision.

While astigmatism is a common condition, it can cause significant visual impairment if left untreated. Regular eye exams are important for detecting and managing astigmatism, as well as other vision problems.